Double-Entry Bookkeeping: 5 Worked Examples for a Business of One
How to record a transaction in double-entry bookkeeping, in five steps, with five fully worked examples, the debit and credit rules, the errors that survive a balanced trial balance, and a month-end checklist.
This article is for educational and informational purposes only and does not constitute financial, tax, legal, or accounting advice. Groundwork is not a licensed financial advisor, accountant, or attorney. Before making decisions, consult a qualified professional.
Double-entry bookkeeping records every transaction twice, once as a debit and once as a credit, so the two sides always balance. Recording one takes five steps. One, identify the two accounts the transaction touches. Two, decide which category each account falls into, since that determines which side increases it. Three, put the amount on the correct side of each. Four, check that total debits equal total credits. Five, confirm the accounting equation still holds. The reason it matters to a one-person business is not tidiness: because every entry has a matching counterpart, an error cannot hide. The books simply stop balancing, and you find out immediately rather than at year end. Most small businesses do not do this by hand, because accounting software applies it automatically behind the scenes. Understanding it still pays off, because it is what lets you tell whether the numbers your software produces are actually right.
- What double-entry bookkeeping actually is
- How to record a transaction: the five steps
- Five worked examples, start to finish
- The debit and credit rules, and how to remember them
- Single-entry versus double-entry: which you need
- The mistakes that break your books
- The month-end checklist
- What your software is doing for you
- Frequently asked questions
Most explanations of double-entry bookkeeping stop at the definition. You learn that every transaction is recorded twice, you nod, and you are no better equipped to record one than you were before.
This guide does the opposite. The definition takes one paragraph, and the rest is worked examples with the actual numbers in place, the rules for deciding which side an amount goes on, and a checklist for catching the errors that a balanced set of books can still hide.
What Double-Entry Bookkeeping Actually Is
Every transaction affects your business in two ways at once. When you buy a laptop for cash, you gain a laptop and you lose cash. Double-entry bookkeeping records both halves. One half is called a debit, the other a credit, and for every transaction the two must be equal.
Debit and credit are the words that cause most of the confusion, because they do not mean what they mean at a bank. Here they are just labels for the two sides of an entry. Debit means the left side. Credit means the right side. Neither means good or bad, and neither means increase or decrease on its own. What they do depends entirely on the type of account, which is what the rules section below sets out.
Underneath sits the accounting equation, which every entry must leave intact:
Assets = Liabilities + Equity
What the business owns equals what it owes plus what the owner has in it.
If an entry ever leaves those two sides unequal, something has been recorded wrongly. That is the whole point of the system, and it is why it has survived essentially unchanged since Venetian merchants formalised it in the fifteenth century.
How to Record a Transaction: The Five Steps
Work through these in order. Once you have done a dozen entries the sequence becomes automatic, but skipping step two is what produces most beginner errors.
Step 1: Identify the two accounts involved
Ask what the business received and what it gave up. Buying stock with cash means the stock account receives and the cash account gives up. Some transactions touch more than two accounts, which is fine, and the totals still have to match.
Step 2: Classify each account
Decide whether each account is an asset, a liability, equity, revenue, or an expense. This step is not optional bookkeeping ceremony. The category is what decides which side increases the account, so getting it wrong reverses the entry.
Step 3: Apply the debit and credit rule
Assets and expenses increase on the debit side. Liabilities, equity, and revenue increase on the credit side. To decrease any account, use the opposite side. The full table is in the rules section below.
Step 4: Check that debits equal credits
Add both sides of the entry. If they do not match, stop and fix it before recording anything else. An unbalanced entry left in place will contaminate every report you run afterwards.
Step 5: Confirm the equation still holds
Assets should still equal liabilities plus equity. This catches the error the previous step cannot: an entry that balances perfectly but was posted to the wrong type of account.
Five Worked Examples, Start to Finish
These are the five transaction shapes that cover most of what a small business does. The numbers are illustrative, chosen to be easy to follow.
Example 1: You invest 5,000 of your own money to start the business
| Account | Type | Debit | Credit |
|---|---|---|---|
| Cash | Asset | 5,000 | |
| Owner's equity | Equity | 5,000 |
Cash is an asset and it increased, so it is debited. Equity increased too, and equity increases on the credit side. The equation holds: assets up 5,000, equity up 5,000.
Example 2: You buy a 1,200 laptop with cash
| Account | Type | Debit | Credit |
|---|---|---|---|
| Equipment | Asset | 1,200 | |
| Cash | Asset | 1,200 |
Two assets, moving in opposite directions. Equipment increased so it is debited; cash decreased so it is credited. Total assets are unchanged, which is correct, because you swapped one asset for another. This is the example that shows why credit does not mean decrease: here it does, but only because cash is an asset.
Example 3: You invoice a client 2,000 for work completed
| Account | Type | Debit | Credit |
|---|---|---|---|
| Accounts receivable | Asset | 2,000 | |
| Revenue | Revenue | 2,000 |
No cash has moved yet. You have a right to be paid, which is an asset, and you have earned revenue. Revenue increases on the credit side. This entry is the one that separates accrual bookkeeping from simply watching your bank balance.
Example 4: The client pays the 2,000 invoice
| Account | Type | Debit | Credit |
|---|---|---|---|
| Cash | Asset | 2,000 | |
| Accounts receivable | Asset | 2,000 |
Notice that no revenue is recorded here. It was already recognised in example 3. Recording it again is one of the most common errors in small business books, and it inflates your reported income by double counting the same work.
Example 5: You pay 400 for software on a credit card
| Account | Type | Debit | Credit |
|---|---|---|---|
| Software expense | Expense | 400 | |
| Credit card payable | Liability | 400 |
Expenses increase on the debit side. The liability increased because you now owe the card issuer, and liabilities increase on the credit side. Cash is untouched, which is exactly why a business can look profitable and still run out of money.
Aziz's take: Example 4 is the one worth burning into memory. Almost every set of small business books I have seen go wrong went wrong there, by recording revenue when the invoice was raised and again when the money landed. It is an easy mistake because both events feel like income arriving. The books still balance perfectly afterwards, which is the cruel part: balancing proves the entries were internally consistent, not that they were right.
The Debit and Credit Rules, and How to Remember Them
There are five account types and only one rule to learn, in two halves.
Increase with a DEBIT
Assets
Expenses
Increase with a CREDIT
Liabilities
Equity
Revenue
To decrease any account, use the other side. That is the entire rule set.
The memory aid most bookkeepers use is DEAL and GIRLS: Debits increase Expenses, Assets, and Losses; Credits increase Gains, Income, Revenue, Liabilities, and Stock (in the sense of shareholder equity). Clumsy, but it sticks, and it beats re-deriving the rule every time.
The intuition worth having alongside it: assets and expenses are things the business has used up or holds, and they sit on the left. Sources of funding, whether borrowed, invested, or earned, sit on the right. Every transaction moves value from a source to a use, which is why the two sides always match.
Single-Entry Versus Double-Entry: Which You Need
Single-entry bookkeeping records each transaction once, like a cheque register. It is faster and it is genuinely adequate for some businesses. The trade-off is that nothing checks your work, and it cannot produce a balance sheet.
Single-entry is defensible if you are a sole trader with few transactions, no stock, no employees, and no debt, and you report on a cash basis. Beyond that, double-entry stops being optional in practice: it is what produces a balance sheet, what lenders and investors expect, and what makes errors visible. Any business carrying stock, extending credit to customers, or owing money should be using it.
The good news is that this is rarely a decision you make consciously any more. Choose more or less any accounting package and double-entry is what runs underneath. Our guide to bookkeeping software for freelancers covers the options, and if you are weighing when to hand the books over entirely, that guide works through the maths.
The Mistakes That Break Your Books
A trial balance that balances is weaker evidence than it feels. These five errors all survive it.
- Recording revenue twice. Once at invoice, once at payment. Covered in example 4, and the most common of all.
- Posting to the right side but the wrong account. Debiting office supplies instead of equipment balances perfectly and quietly misstates both your expenses and your assets.
- Reversing an entry. Debiting what should have been credited puts your books out by exactly twice the amount, which is why an error divisible by two is worth checking for a reversal.
- Transposing digits. Entering 540 as 450. A discrepancy divisible by nine is the classic fingerprint of a transposition.
- Omitting a transaction entirely. Nothing detects this, because a missing entry breaks nothing. Only reconciling against your bank statement catches it.
The Month-End Checklist
Run this once a month. It takes under an hour for a small business and it catches the errors above before they compound.
- Reconcile every bank and credit card account against its statement, line by line.
- Confirm total debits equal total credits on the trial balance.
- Check the accounting equation still holds: assets equal liabilities plus equity.
- Review accounts receivable and confirm each open invoice is genuinely still unpaid.
- Review accounts payable the same way, so you are not carrying bills you already settled.
- Scan the expense accounts for anything posted to an obviously wrong category.
- If the books are out, check whether the difference divides by nine (transposition) or by two (reversal) before hunting line by line.
- Confirm no revenue was recorded twice for the same piece of work.
Once the books balance and reconcile, the reports built on them are trustworthy. Our guide to reading a profit and loss statement covers what to do with them next, and managing cash flow explains why a profitable set of books can still leave you short of money.
What Your Software Is Doing for You
If you use accounting software, it is already applying everything above. When you categorise a bank transaction, you are choosing the second account; the software knows the first was cash and applies the debit and credit rule for you.
Which raises the fair question of why any of this is worth knowing. The answer is that software applies the rule correctly and still cannot tell whether you pointed it at the right account. It will happily record revenue twice if you tell it to. Understanding the mechanics is what lets you look at a report and notice that something is wrong, rather than trusting an output you have no way of checking.
For the wider picture of how these pieces fit together, our complete guide to small business finance is the place to start.
Frequently Asked Questions
