QA Team Training

ERP Deep Dive: Understanding Commas Inside Out

This guide teaches you everything you need to know about ERP systems and how Commas works under the hood. No accounting background required — we explain every concept from scratch using plain language and real-world analogies.

By the end of this session, you will understand what every module does, why financial transactions must always balance, how data flows through the system, and what to look for when testing each feature.

Sections

Minutes

Prerequisites

100%

Practical

1What Is an ERP?

~5 minutes

ERP stands for Enterprise Resource Planning. Despite the intimidating name, the concept is simple: it is a single software system that manages all the core operations of a business in one place.

Think of it this way

Imagine you run a shop. You have one notebook for tracking what you sell (sales), another for what you buy (purchases), another for your bank balance, another for what customers owe you, and another for your employees' salaries. An ERP is like combining all those notebooks into one big book where everything is connected. When you record a sale, it automatically updates your inventory, your bank balance, and what the customer owes you.

What does an ERP manage?

Business Area	What It Covers	In Commas
Finance & Accounting	General ledger, chart of accounts, financial statements	Chart of Accounts, Journals, Trial Balance, P&L, Balance Sheet
Sales	Quotes, orders, invoices, receipts, credit notes	Quotes > Orders > Invoices > Receipts
Purchasing	Purchase orders, bills, goods receipt, returns	POs > Goods Receipt > Bills > Payments
Inventory	Stock levels, movements, counts, valuation	Items, Stock Levels, Stock Count, Movements
Banking	Bank accounts, reconciliation, payments	Bank Accounts, Reconciliation, Batch Payments
Tax & Compliance	VAT/GST returns, tax calculations	VAT Returns, VAT Adjustments, Tax Payments
Payroll	Employee management, salary, deductions	Employees, Pay Runs, Payslips
Reporting	Financial reports, analytics, dashboards	49+ reports including Trial Balance, P&L, Balance Sheet
Administration	Users, roles, permissions, audit trail	User Management, 70+ Permissions, Audit Log

The Golden Rule of ERP

Everything is connected. When you create a sales invoice in Commas, the system simultaneously: (1) records the sale as revenue, (2) records the VAT owed to the government, (3) records what the customer owes you, and (4) updates the general ledger. This is not four separate actions — it is one atomic operation. This interconnectedness is what makes testing an ERP different from testing a simple CRUD app.

How Commas implements this

Commas is a cloud-based, multi-tenant ERP designed specifically for SMEs in Nigeria and South Africa. It runs on Next.js + Supabase (PostgreSQL), uses Row-Level Security for data isolation, and implements double-entry bookkeeping with a central posting engine. Every financial transaction goes through this engine, guaranteeing that the books always balance.

2Double-Entry Bookkeeping

~10 minutes — This is the most important concept in the entire system

Double-entry bookkeeping is a 500-year-old system invented in Italy. It is the foundation of every accounting system in the world, including Commas. The core rule is devastatingly simple:

Every transaction has two sides.

For every debit, there must be an equal credit.

Total Debits = Total Credits — Always.

Think of it this way

Think of your personal life. You buy a laptop for ₦200,000 using your bank account. Two things happened simultaneously: (1) you gained a laptop (asset goes up), and (2) your bank balance went down by ₦200,000. The money didn't vanish — it changed form. Double-entry bookkeeping simply records both sides of every transaction.

Debits and Credits

Forget what "debit" and "credit" mean in everyday language. In accounting, they are simply the left side and right side of a journal entry. Which side increases or decreases depends on the type of account:

Account Type	Increased By	Decreased By	Normal Balance	Example
Asset	Debit	Credit	Debit	Bank, Accounts Receivable, Inventory, Equipment
Liability	Credit	Debit	Credit	Accounts Payable, Loans, VAT Payable
Equity	Credit	Debit	Credit	Owner's Capital, Retained Earnings
Revenue	Credit	Debit	Credit	Sales Revenue, Service Income
Expense	Debit	Credit	Debit	Rent, Salaries, Utilities, Cost of Goods

The DEALER mnemonic

Debits increase DEAL accounts (Dividends, Expenses, Assets, Losses). Credits increase CRIG accounts (Capital, Revenue, Income, Gains). This is all you need to remember.

Example: Recording a Sale

Adebayo Trading sells 10 laptops at ₦100,000 each to a customer on credit (they will pay later). VAT is 7.5%.

Journal Entry: Sales Invoice #INV-001

Total sale = 10 × ₦100,000 = ₦1,000,000 VAT = ₦1,000,000 × 7.5% = ₦75,000 Total invoice = ₦1,075,000 Date: 2026-05-15 Reference: INV-001 Account Debit (₦) Credit (₦) ───────────────────────────────────────────────────── Accounts Receivable 1,075,000 Sales Revenue 1,000,000 VAT Output 75,000 ───────────────────────────────────────────────────── TOTAL 1,075,000 1,075,000 ✓ Balanced

What just happened? Three things were recorded in one transaction:

Accounts Receivable (asset) went UP by ₦1,075,000 — the customer owes us money
Sales Revenue (revenue) went UP by ₦1,000,000 — we earned income
VAT Output (liability) went UP by ₦75,000 — we collected tax that we owe the government

Example: Receiving Payment

The customer pays the full ₦1,075,000 into our bank account.

Journal Entry: Receipt #REC-001

Date: 2026-05-20 Reference: REC-001 Account Debit (₦) Credit (₦) ───────────────────────────────────────────────────── Bank (Asset) 1,075,000 Accounts Receivable 1,075,000 ───────────────────────────────────────────────────── TOTAL 1,075,000 1,075,000 ✓ Balanced

Now: Bank went UP (we received cash), Accounts Receivable went DOWN (customer no longer owes us). The money moved from "owed to us" to "in our bank". Total debits still equal total credits.

How Commas implements this

In Commas, you never manually type journal entries for sales, purchases, or payments. Instead, you create documents (invoices, bills, receipts) and click "Post". The posting engine automatically generates the correct double-entry journal entries behind the scenes. The General Ledger > Journal Entries page shows you what was generated. As a tester, you should verify that every posted document creates a balanced journal entry.

3Chart of Accounts

~7 minutes

The Chart of Accounts (CoA) is the master list of every account in the system. Think of it as the filing system for all money that flows through the business. Every transaction touches at least two accounts from this list.

Think of it this way

If your business were a library, the Chart of Accounts would be the Dewey Decimal System — it defines the categories and subcategories where every "book" (transaction) gets filed. Without it, you'd have a pile of transactions with no organization.

The Five Account Types

Every account in the Chart of Accounts belongs to exactly one of five types. These five types are the building blocks of all financial reporting:

Balance Sheet Accounts

These accounts carry forward forever. They represent what you have, what you owe, and what belongs to the owners.

1. Assets — What the business owns (cash, equipment, inventory, receivables)
2. Liabilities — What the business owes (loans, payables, tax owed)
3. Equity — The owner's stake (capital invested + accumulated profits)

Income Statement Accounts

These accounts reset to zero at year-end. They measure performance during a period.

4. Revenue — Money earned (sales, services, interest income)
5. Expenses — Money spent to earn that revenue (rent, salaries, supplies)

The Accounting Equation

Assets = Liabilities + Equity

This equation must always hold true. If assets are ₦10 million, then liabilities plus equity must also be ₦10 million. The Balance Sheet report proves this. If it doesn't balance, something is seriously wrong.

Account Numbering Convention

Commas auto-generates a Chart of Accounts when you create an organization. Accounts are numbered:

Number Range	Type	Examples
1000 – 1999	Assets	1000 Cash, 1100 Bank, 1200 Accounts Receivable, 1300 Inventory
2000 – 2999	Liabilities	2000 Accounts Payable, 2100 VAT Payable, 2200 Loans
3000 – 3999	Equity	3000 Owner's Capital, 3100 Retained Earnings
4000 – 4999	Revenue	4000 Sales Revenue, 4100 Service Income, 4200 Interest Income
5000 – 5999	Cost of Sales	5000 Cost of Goods Sold
6000 – 7999	Expenses	6000 Salaries, 6100 Rent, 6200 Utilities, 6300 Office Supplies

How Commas implements this

Navigate to General Ledger > Chart of Accounts to see the full list. You can add new accounts, edit existing ones, and see the running balance for each. Accounts can be marked as "header" (grouping only, no transactions posted) or "posting" (accepts transactions). When testing, verify that the default CoA is generated correctly for Nigeria (NGN) and South Africa (ZAR).

4The General Ledger

~5 minutes

The General Ledger (GL) is the complete record of every financial transaction that has ever happened in the business. It is the single source of truth. Every report in the system — Trial Balance, Income Statement, Balance Sheet — is generated by reading from the General Ledger.

Think of it this way

If the Chart of Accounts is the filing system, the General Ledger is the actual filing cabinet with all the documents in it. Each drawer (account) contains every transaction that touched that account, in chronological order.

Journal Entries

The GL is made up of journal entries. Each journal entry has:

Date — When the transaction occurred
Reference — The document that caused it (e.g., INV-001, BILL-005)
Lines — Two or more lines, each hitting a different account with a debit or credit
Narration — A human-readable description

How Documents Become Journal Entries

┌──────────┐ ┌──────────┐ ┌──────────┐ │ Invoice │ │ Bill │ │ Receipt │ │ (Sales) │ │(Purchase)│ │(Payment) │ └─────┬─────┘ └─────┬────┘ └─────┬────┘ │ │ │ └────────┬────────┘ │ │ │ ┌────────▼────────┐ │ │ POSTING ENGINE │◄────────────────┘ │ (validates that │ │ debits = credits│ │ then inserts) │ └────────┬────────┘ │ ┌────────▼────────┐ │ GENERAL LEDGER │ ← Single source of truth │ (journal_entries│ │ + gl_lines) │ └────────┬────────┘ │ ┌────────────┼────────────┐ │ │ │ ┌───▼──┐ ┌────▼───┐ ┌───▼────┐ │Trial │ │Income │ │Balance │ │Balance│ │Statement│ │ Sheet │ └──────┘ └────────┘ └────────┘

How Commas implements this

Navigate to General Ledger > Journal Entries to see all entries. You can also create manual journal entries (for adjustments, corrections, or accruals). When testing, the most critical check is: after posting any document, navigate to Journal Entries and verify that a new balanced entry was created with the correct accounts and amounts.

5Subledgers (The Detail Behind the Summary)

~10 minutes — This is where the magic of an ERP really shines

The General Ledger tells you that "Accounts Receivable is ₦5,000,000" but it doesn't tell you which customers owe that money. That's what subledgers are for.

A subledger (also called a subsidiary ledger) is a detailed breakdown of a single GL account. The total of all entries in the subledger must always equal the balance in the corresponding GL account. This is called reconciliation.

Think of it this way

The General Ledger is like a company-wide scorecard: "We are owed ₦5 million." The Customer Subledger is the detailed list: "Customer A owes ₦2M, Customer B owes ₦1.5M, Customer C owes ₦1.5M." The sum of the parts must always equal the whole.

Commas Has Five Subledgers

Subledger	Tracks	Related GL Account	Key Reports
Customer Ledger	What each customer owes you (Accounts Receivable)	Accounts Receivable (Asset)	Customer Statement, AR Aging, Customer Ledger Entries
Vendor Ledger	What you owe each supplier (Accounts Payable)	Accounts Payable (Liability)	Vendor Statement, AP Aging, Vendor Ledger Entries
Bank Ledger	Every transaction in each bank account	Bank (Asset)	Bank Statement, Bank Reconciliation
Inventory Ledger	Stock quantities and cost per item	Inventory (Asset)	Stock Levels, Stock Movements, Valuation Report
VAT Ledger	Tax collected (output) and tax paid (input)	VAT Output / VAT Input (Liability/Asset)	VAT Return, VAT Summary

Customer Ledger Deep Dive

Let's trace a full customer lifecycle:

Customer Ledger: Adebayo Trading → Customer 'Lagos Electronics'

Date Document Type Debit (₦) Credit (₦) Balance (₦) ───────────────────────────────────────────────────────────────────────── 2026-05-01 INV-001 Invoice 1,075,000 1,075,000 2026-05-10 REC-001 Receipt 500,000 575,000 2026-05-20 INV-002 Invoice 537,500 1,112,500 2026-05-25 CN-001 Credit Note 107,500 1,005,000 2026-05-30 REC-002 Receipt 1,005,000 0 ───────────────────────────────────────────────────────────────────────── GL Account "Accounts Receivable" balance should = Sum of all customer balances

Vendor Ledger Deep Dive

The vendor ledger works the same way but in reverse — it tracks what you owe:

Vendor Ledger: Adebayo Trading → Supplier 'China Imports Ltd'

Date Document Type Debit (₦) Credit (₦) Balance (₦) ───────────────────────────────────────────────────────────────────────── 2026-05-02 BILL-001 Bill 2,150,000 2,150,000 2026-05-15 PAY-001 Payment 1,000,000 1,150,000 2026-05-28 PAY-002 Payment 1,150,000 0 ───────────────────────────────────────────────────────────────────────── GL Account "Accounts Payable" balance should = Sum of all vendor balances

Inventory Ledger Deep Dive

The inventory ledger tracks the quantity and cost of each item:

Inventory Ledger: Item 'HP Laptop ProBook 450'

Date Document Type Qty In Qty Out Balance Unit Cost (₦) ────────────────────────────────────────────────────────────────────────────────── 2026-05-02 PO-001 Purchase 50 50 85,000 2026-05-15 INV-001 Sale 10 40 85,000 2026-05-20 INV-002 Sale 5 35 85,000 2026-05-25 ADJ-001 Stock Adjustment -2 33 85,000 ────────────────────────────────────────────────────────────────────────────────── GL Account "Inventory" balance should = Sum of (quantity × unit cost) for all items

The Reconciliation Principle

The sum of every subledger must equal its parent GL account. If the Customer Ledger says customers owe ₦5M total, the Accounts Receivable GL account must also show ₦5M. If they don't match, there's a bug. This is a critical test case for QA.

How Commas implements this

Each subledger has its own section in the sidebar: Customers > Customer Ledger, Suppliers > Vendor Ledger, Banking > Bank Ledger, etc. The posting engine writes to both the GL and the relevant subledger simultaneously. When testing, always verify both: check that the GL entry is balanced AND that the subledger entry matches.

6Financial Statements

~8 minutes

Financial statements are the output of the accounting system. They are generated automatically from the General Ledger data. There are four main statements:

1. Trial Balance

The Trial Balance lists every account and its balance (debit or credit). Its purpose is to prove that total debits = total credits. If they don't match, something was posted incorrectly.

Trial Balance as at 31 May 2026 (simplified)

Account Debit (₦) Credit (₦) ────────────────────────────────────────────────────────── Bank 3,500,000 Accounts Receivable 1,005,000 Inventory 2,805,000 Equipment 500,000 Accounts Payable 1,150,000 VAT Payable 225,000 Owner's Capital 5,000,000 Retained Earnings 200,000 Sales Revenue 3,000,000 Cost of Goods Sold 1,275,000 Salaries Expense 350,000 Rent Expense 100,000 Utilities Expense 40,000 ────────────────────────────────────────────────────────── TOTAL 9,575,000 9,575,000 ✓

2. Income Statement (Profit & Loss)

The Income Statement answers: "Did we make money or lose money this period?"It shows Revenue minus Expenses = Net Profit (or Loss).

Income Statement: May 2026

₦ ────────────────────────────────────────────── REVENUE Sales Revenue 3,000,000 ────────── Total Revenue 3,000,000 COST OF SALES Cost of Goods Sold 1,275,000 ────────── Gross Profit 1,725,000 OPERATING EXPENSES Salaries 350,000 Rent 100,000 Utilities 40,000 ────────── Total Expenses 490,000 ────────────────────────────────────────────── NET PROFIT 1,235,000 ──────────────────────────────────────────────

3. Balance Sheet

The Balance Sheet is a snapshot of "What do we own, what do we owe, and what's left for the owners?" at a specific moment in time. It must always satisfy:

Assets = Liabilities + Equity

Balance Sheet as at 31 May 2026

₦ ────────────────────────────────────────────── ASSETS Current Assets Bank 3,500,000 Accounts Receivable 1,005,000 Inventory 2,805,000 Non-Current Assets Equipment 500,000 ────────── TOTAL ASSETS 7,810,000 LIABILITIES Current Liabilities Accounts Payable 1,150,000 VAT Payable 225,000 ────────── TOTAL LIABILITIES 1,375,000 EQUITY Owner's Capital 5,000,000 Retained Earnings 200,000 Net Profit (current period) 1,235,000 ────────── TOTAL EQUITY 6,435,000 ────────────────────────────────────────────── LIABILITIES + EQUITY 7,810,000 ────────────────────────────────────────────── BALANCED? ✓ (7,810,000 = 7,810,000)

4. Cash Flow Statement

Shows where cash came from and where it went, categorized into operating activities (daily business), investing activities (buying/selling assets), and financing activities (loans, owner contributions).

How Commas implements this

All four statements are available under Reports in the sidebar. They are generated in real-time from GL data. Key QA checks: (1) Trial Balance must always balance, (2) Balance Sheet equation must hold, (3) Net Profit on the Income Statement must match the "Net Profit" line on the Balance Sheet, (4) reports should respect date range filters.

7Document Flow in Commas

~8 minutes

Commas follows an industry-standard document flow inspired by Microsoft Dynamics Business Central. Documents progress through statuses and can be converted from one type to another.

Sales Flow (Order-to-Cash)

Sales Document Flow

┌─────────┐ ┌──────────────┐ ┌──────────┐ ┌──────────┐ │ QUOTE │───▶│ SALES ORDER │───▶│ INVOICE │───▶│ RECEIPT │ │ (Draft) │ │ (Released) │ │ (Posted) │ │(Applied) │ └─────────┘ └──────────────┘ └──────────┘ └──────────┘ │ │ │ Direct conversion │ └────────────────────────────────────┘ QUOTE statuses: Draft → Sent → Accepted → Converted ORDER statuses: Draft → Released → Partial → Invoiced → Closed INVOICE statuses: Draft → Posted → Partial → Paid Special flows: • Quote can convert directly to Invoice (skipping Order) • Order supports partial invoicing (invoice some lines now, rest later) • Credit Notes reverse invoices (with GL reversal)

Purchase Flow (Procure-to-Pay)

Purchase Document Flow

┌───────────────┐ ┌────────────────┐ ┌────────┐ ┌─────────┐ │PURCHASE ORDER │───▶│ GOODS RECEIPT │───▶│ BILL │───▶│ PAYMENT │ │ (Released) │ │ (Received) │ │(Posted)│ │(Applied)│ └───────────────┘ └────────────────┘ └────────┘ └─────────┘ PO statuses: Draft → Released → Partial → Received → Closed BILL statuses: Draft → Posted → Partial → Paid Three-Way Matching: PO amount ↔ Goods Receipt quantity ↔ Bill amount (All three must agree before payment is authorized)

Document Statuses Explained

Status	Meaning	Can Edit?	GL Impact?
Draft	Document is being prepared, not yet final	Yes	No — nothing posted to GL yet
Posted	Document is finalized and GL entries created	No	Yes — journal entries created
Partial	Partially paid or partially fulfilled	No	Yes — some payments/receipts applied
Paid / Closed	Fully settled or completed	No	Yes — fully reconciled
Cancelled / Voided	Document reversed	No	Yes — reversal entries created

Draft vs Posted — The Critical Distinction

A draft document has ZERO financial impact. It's just a saved form. Only when a document is posted does it create journal entries and affect the GL. This is an essential test case: verify that draft documents do NOT appear in financial reports, and posted documents DO.

How Commas implements this

Every document page in Commas follows the same pattern: a list view with status badges, a detail view with action buttons (Post, Pay, Convert), and a form view for creation/editing. The status badge is color-coded: gray for draft, blue for posted, yellow for partial, green for paid/closed, red for cancelled. When testing, verify that all status transitions work correctly and that invalid transitions are blocked (e.g., you cannot edit a posted invoice).

8The Posting Engine

~5 minutes

The posting engine is the heart of Commas. It is a single function that every module calls when a document needs to create financial entries. It guarantees that:

Total debits always equal total credits (balanced entries)
The correct accounts are used (via Posting Groups)
Subledger entries are created alongside GL entries
The operation is atomic (all or nothing — if any part fails, nothing is saved)

Posting Groups

Posting Groups are configuration rules that tell the posting engine whichGL accounts to use. Instead of hardcoding "when selling goods, credit account 4000", the system looks up the Posting Group:

Posting Group Type	Purpose	Example Configuration
General Business Posting Group	Categorizes customers/vendors by type	DOMESTIC, FOREIGN, GOVERNMENT
General Product Posting Group	Categorizes items by type	GOODS, SERVICES, MATERIALS
General Posting Setup	Maps Business × Product → GL Accounts	DOMESTIC + GOODS → Sales Account 4000, COGS Account 5000
Customer Posting Group	Maps customer type → AR account	TRADE → AR Account 1200
Vendor Posting Group	Maps vendor type → AP account	TRADE → AP Account 2000
Inventory Posting Group	Maps item type → inventory GL account	GOODS → Inventory Account 1300

Think of it this way

Posting Groups are like a recipe book for the posting engine. When you post an invoice for selling GOODS to a DOMESTIC customer, the engine looks up the recipe: "DOMESTIC + GOODS → credit Sales Revenue (4000), debit COGS (5000), debit AR (1200)". This makes the system flexible — different product types can post to different GL accounts.

Posting Engine Flow

User clicks "Post Invoice" │ ▼ ┌─────────────────────┐ │ Validate document │ ← Check all required fields are present │ (lines, amounts, │ │ customer, dates) │ └──────────┬──────────┘ │ ▼ ┌─────────────────────┐ │ Look up Posting │ ← Determine which GL accounts to use │ Groups (Business + │ │ Product → Accounts) │ └──────────┬──────────┘ │ ▼ ┌─────────────────────┐ │ Build journal entry │ ← Create debit/credit lines │ lines (with VAT │ │ calculation) │ └──────────┬──────────┘ │ ▼ ┌─────────────────────┐ │ Verify debits = │ ← CRITICAL: reject if unbalanced │ credits │ └──────────┬──────────┘ │ ▼ ┌─────────────────────┐ │ Insert into GL │ ← Write to journal_entries + gl_lines │ + subledger entries │ ← Write to customer_ledger_entries etc. │ + update document │ ← Mark document as "posted" │ (all in one │ │ transaction) │ ← Atomic: all or nothing └─────────────────────┘

How Commas implements this

The posting engine lives in lib/services/posting.service.ts. When testing, the key things to verify are: (1) every posted document creates balanced GL entries, (2) the correct GL accounts are used based on Posting Groups, (3) if you misconfigure a Posting Group (leave an account blank), the posting should fail gracefully with an error message, not create partial entries.

9Multi-Tenant Architecture & Security

~5 minutes

Commas is a multi-tenant application. This means multiple companies (organizations) share the same database and application, but each one can only see their own data.

Think of it this way

Think of an apartment building. Everyone lives in the same building (same database), but each tenant has their own apartment with a lock on the door. You can't walk into your neighbor's apartment. That's multi-tenancy.

How Data Isolation Works

Every table in the database has an org_id column. This is the "apartment number". Supabase Row-Level Security (RLS) policies automatically filter data so that users can only see rows where org_id matches their organization.

Row-Level Security Example

Table: invoices ───────────────────────────────────────────────── id org_id invoice_no total ───────────────────────────────────────────────── inv-001 org-AAA INV-001 1,075,000 ← Visible to org-AAA users inv-002 org-AAA INV-002 537,500 ← Visible to org-AAA users inv-003 org-BBB INV-001 2,300,000 ← Visible to org-BBB users inv-004 org-CCC INV-001 750,000 ← Visible to org-CCC users ───────────────────────────────────────────────── When User from org-AAA queries: SELECT * FROM invoices They ONLY see inv-001 and inv-002. RLS hides the rest.

Roles & Permissions

Within each organization, users are assigned roles. Commas has 12 built-in roles:

Role	Access Level	Example Permissions
Owner	Full access to everything	All permissions + can delete org, manage billing
Admin	Full access to everything	All permissions except org deletion
Finance Manager	Full financial access	All financial operations, reports, journals
Accountant	Day-to-day accounting	Invoices, bills, receipts, journals, reports
Sales User	Sales operations only	Quotes, invoices, receipts, customers
Purchasing User	Purchasing operations only	POs, bills, payments, suppliers
Inventory User	Inventory operations only	Items, stock levels, counts, movements
Bank User	Banking operations only	Bank accounts, reconciliation, transfers
Payroll Admin	Payroll operations	Employees, pay runs, payslips
Auditor	Read-only access to everything	Can view all data but cannot create or modify
Read Only	Read-only access to assigned areas	View permissions only
Member	Basic access	Dashboard and profile only

There are 70+ granular permissions (like view_invoices, create_invoices, post_invoices, delete_invoices) that can be customized per role via the Access Control page.

How Commas implements this

When testing: (1) Create two organizations and verify data is completely isolated between them, (2) Test each role by changing a user's role and verifying they can only access permitted pages, (3) Verify that the Admin > Access Control page correctly shows and toggles permissions, (4) Verify the audit log captures who did what and when.

10Commas Modules Overview

~7 minutes

Here is a complete map of every module in Commas and what it does:

General Ledger

Feature	What It Does	Key Test Cases
Chart of Accounts	Master list of all accounts	Default CoA generated, accounts CRUD, balance display
Journal Entries	Manual and auto-generated GL entries	Create manual entry, verify balanced, view auto-generated
Posting Groups	Maps documents to GL accounts	Business/Product/Customer/Vendor groups configured correctly
Opening Balances	Set initial balances for migration	Post GL/customer/supplier/bank opening balances, verify TB

Sales

Feature	What It Does	Key Test Cases
Quotes	Create proposals for customers	CRUD, status flow (draft→sent→accepted→converted), convert to invoice/order
Sales Orders	Confirmed orders before invoicing	CRUD, release, partial invoicing, full invoicing, convert from quote
Invoices	Bills sent to customers	CRUD, post (verify GL), email/PDF, credit notes, recurring templates
Receipts	Record customer payments	Create, apply to invoice, verify bank + AR updated, over/under payment
Credit Notes	Reverse/adjust invoices	Create from invoice, post (verify GL reversal), apply to balance
Recurring Invoices	Auto-generate invoices on schedule	Create template, generate now, verify frequency calculation

Purchasing

Feature	What It Does	Key Test Cases
Purchase Orders	Orders sent to suppliers	CRUD, release, goods receipt, 3-way matching
Goods Receipt	Record received inventory	Receive against PO, partial receive, verify stock updated
Bills	Invoices from suppliers	CRUD, post (verify GL), create from PO
Payments	Pay supplier bills	Create, apply to bill, batch payments, verify bank + AP
Purchase Returns	Return goods to suppliers	Create return, auto credit note, verify stock adjustment

Banking

Feature	What It Does	Key Test Cases
Bank Accounts	Manage bank account records	CRUD, linked GL account, running balance
Reconciliation	Match bank statement to system records	Upload statement, auto-match, manual match, post differences
Transfers	Move money between bank accounts	Create, verify both accounts updated, GL entries balanced
Bank Feeds	Auto-import transactions	Connect feed, mapping rules, auto-categorization

Inventory

Feature	What It Does	Key Test Cases
Items	Product/service catalog	CRUD, item categories, units, pricing, posting groups
Stock Levels	Current quantity per item per location	Verify updates after sale/purchase, low stock alerts
Stock Counts	Physical inventory verification	Create count, enter actual qty, post adjustments
Stock Movements	Transfer between locations	Create movement, verify source/destination updated
Bundles	Kits / composite items	Create bundle with components, verify stock deduction on sale

Other Modules

Module	Features	Key Test Cases
Payroll	Employees, pay runs, payslips, deductions	Create employee, run payroll, verify deductions, generate payslips
VAT & Tax	VAT returns, adjustments, payments	Generate return from transactions, file, pay, verify GL
Reports (49+)	Trial Balance, P&L, Balance Sheet, aging, etc.	Date filters, data accuracy, CSV/PDF export, print
Expenses	Expense claims and petty cash	Create expense, approve, reimburse, verify GL
Debtors Management	Collections, write-offs, communication	Aging buckets, send reminders, write off bad debt
Administration	Users, roles, audit log, settings	Invite user, change role, verify permissions, check audit trail
Accountant Tools	External accountant portal	Invite accountant, shared notes, recurring journals, TB export

11Testing an ERP: What to Look For

~5 minutes

Testing an ERP is fundamentally different from testing a regular web application. Here are the specific things you should always check:

1. Financial Integrity Checks

These are the highest priority. A financial bug can cause real monetary harm to users.

⚠Trial Balance must always balance — After any operation, total debits must equal total credits
⚠Balance Sheet equation must hold — Assets = Liabilities + Equity, always
⚠Subledger reconciliation — Sum of customer balances = AR account balance
⚠VAT calculations — 7.5% in Nigeria, 15% in South Africa, applied correctly
⚠No rounding errors — Amounts must use proper decimal handling, no floating-point issues

2. Status Flow Checks

Documents can only move through valid status transitions (Draft → Posted, not Posted → Draft)
Draft documents cannot appear in financial reports
Posted documents cannot be edited (only reversed via credit notes)
Cancelled documents create reversal entries in the GL

3. Data Isolation Checks

Organization A cannot see Organization B's data (test with two browser sessions)
Document numbers are unique per organization (both orgs can have INV-001)
Switching orgs clears all cached data from the previous org

4. Cross-Module Consistency

After posting a sales invoice: check GL, customer ledger, inventory ledger, and VAT ledger
After recording a payment: check bank ledger AND the invoice status changed to "Paid"
After a stock count adjustment: check inventory GL account matches new valuation
After a credit note: check the original invoice balance and the GL reversal

5. Edge Cases

Zero-amount invoices and credit notes
Overpayments (pay more than the invoice amount)
Partial payments across multiple invoices
Converting a quote with many line items (10+)
Items with 0% VAT rate
Deleting the last owner of an organization (should be blocked)
Very large amounts (test with amounts over ₦1 billion)
Special characters in customer/supplier names
Backdated transactions (posting to a previous month)

6. The "Follow the Money" Test

The Ultimate ERP Test

Pick any business scenario (sell goods, buy inventory, pay salaries) and trace the money through every system it touches. If you sell goods on credit and then receive payment, you should be able to see: (1) the invoice, (2) the GL journal entry from the invoice, (3) the customer ledger entry, (4) the receipt, (5) the GL journal entry from the receipt, (6) the bank ledger entry, (7) the invoice status changed to "Paid", (8) the customer balance went to zero. If any link in the chain is missing or wrong, you've found a bug.

12ERP Glossary

Quick reference for terms you will encounter

Term	Definition	Example in Commas
Account	A category for recording transactions	Sales Revenue (4000), Bank (1100)
Accounts Payable (AP)	Money you owe to suppliers	Vendor Ledger shows AP per supplier
Accounts Receivable (AR)	Money customers owe you	Customer Ledger shows AR per customer
Aging Report	Shows overdue amounts by time bucket (30/60/90 days)	Reports > AR Aging or AP Aging
Balance Sheet	Snapshot of Assets, Liabilities, Equity at a point in time	Reports > Balance Sheet
Bill	Invoice FROM a supplier (what you owe them)	Purchasing > Bills
Chart of Accounts (CoA)	Master list of all accounts in the system	General Ledger > Chart of Accounts
Credit Note	Reversal or reduction of an invoice	Sales > Credit Notes or Purchasing > Credit Notes
Debit	Left side of a journal entry	Increases assets and expenses
Credit	Right side of a journal entry	Increases liabilities, equity, and revenue
Double Entry	Every transaction has equal debits and credits	All postings in Commas use double-entry
Fiscal Year	The 12-month period used for financial reporting	Settings > Organization > Financial Year
General Ledger (GL)	Complete record of all financial transactions	General Ledger > Journal Entries
Goods Receipt	Recording that inventory was physically received	Purchasing > Purchase Orders > Receive
Income Statement	Revenue minus Expenses = Profit or Loss	Reports > Income Statement (P&L)
Invoice	Bill sent to a customer for goods/services	Sales > Invoices
Journal Entry	A set of debit/credit lines that record a transaction	General Ledger > Journal Entries
Narration	Description text on a journal entry	Auto-generated or manual description
Opening Balance	Starting balances when migrating to a new system	Settings > Opening Balances
Posting	Finalizing a document to create GL entries	Click "Post" on an invoice or bill
Posting Group	Configuration that maps documents to GL accounts	Settings > Posting Groups
Purchase Order (PO)	Formal request to buy goods from a supplier	Purchasing > Purchase Orders
Quote	Price proposal sent to a customer	Sales > Quotes
Receipt	Record of payment received from a customer	Sales > Receipts
Reconciliation	Matching system records to external records (bank statement)	Banking > Reconciliation
RLS	Row-Level Security — database enforces data isolation per org	Every table filtered by org_id
Sales Order	Confirmed customer order before invoicing	Sales > Sales Orders
Subledger	Detailed breakdown of a GL account by entity	Customer Ledger, Vendor Ledger, Bank Ledger
Three-Way Match	Matching PO + Goods Receipt + Bill before payment	Purchasing module verification
Trial Balance	List of all account balances (must balance)	Reports > Trial Balance
VAT	Value Added Tax — 7.5% Nigeria, 15% South Africa	Auto-calculated on invoices and bills