Double-Entry Bookkeeping: Rules and Examples for Beginners

Quick answer: Double-entry bookkeeping records every transaction in at least two accounts, with total debits equal to total credits. Debits increase assets, expenses and draws; credits increase liabilities, equity and revenue. Because both sides are always recorded, assets always equal liabilities plus equity, and errors are easier to catch.

Debits and credits confuse almost everyone who starts double-entry bookkeeping, mostly because banks use the words in the opposite way to bookkeepers. This beginner's guide explains the accounting equation, gives you the debit and credit rules in one table, shows how T-accounts work, and walks through a startup's first transactions with the equation checked after every step. If you have read our bookkeeping basics overview, this is the next layer down.

On scope: the invoice generator on this site creates PDF invoices in your browser. It does not record debits and credits or keep books. You will record each invoice in your accounting software or spreadsheet, and this guide explains what that recording does behind the scenes.

What is double-entry bookkeeping?

The method rests on one equation:

Assets = Liabilities + Equity

Assets are what the business owns or is owed (cash, receivables, equipment). Liabilities are what it owes to others (supplier bills, loans, sales tax collected). Equity is the owner's stake: money put in plus profits kept, minus draws. Revenue increases equity and expenses decrease it, so they sit inside the equity side of the equation until year-end.

Every transaction changes at least two items in a way that keeps the equation true. Borrow $5,000 and cash (an asset) rises by $5,000 while the loan (a liability) also rises by $5,000. Pay a $1,200 wage and cash falls by $1,200 while equity falls by $1,200 through the expense. Recording both sides of every change is what the term "double entry" means.

Single-entry vs double-entry

Feature	Single-entry	Double-entry
How transactions are recorded	Once, as money in or out	Twice or more, as debits and credits
Tracks assets and liabilities	Not systematically	Yes
Produces a balance sheet	Not easily	Yes
Built-in error check	No	Yes: debits must equal credits
Best for	Very small, cash-only activity	Any business with receivables, payables, loans or assets

The US Small Business Administration's guidance on managing your business finances covers recordkeeping more broadly. In practice, almost all accounting software uses double-entry, even when the interface hides the debits and credits.

The rules of debits and credits

A debit is an entry on the left side of an account and a credit is an entry on the right. Whether each one increases or decreases a balance depends on the type of account.

Account type	Increase with	Decrease with	Normal balance
Assets	Debit	Credit	Debit
Expenses	Debit	Credit	Debit
Owner's draws or dividends	Debit	Credit	Debit
Liabilities	Credit	Debit	Credit
Equity (capital)	Credit	Debit	Credit
Revenue	Credit	Debit	Credit

The DEALER memory aid

Read the word in two halves. DEA: Dividends (or Drawings), Expenses and Assets increase with debits. LER: Liabilities, Equity and Revenue increase with credits. If you remember only that, you can work out any entry.

The traditional golden rules

Many students in India, Pakistan and elsewhere learn a different framing that produces the same entries:

• Personal accounts (people and organizations): debit the receiver, credit the giver.
• Real accounts (assets): debit what comes in, credit what goes out.
• Nominal accounts (income and expenses): debit expenses and losses, credit income and gains.

Why your bank seems backward

When your bank "credits" your account, your balance goes up. That is because your deposit is a liability on the bank's books: it owes you the money. On your own books, the same cash is an asset, so you debit it. Neither is wrong; they are opposite sides of the same relationship.

T-accounts: seeing both sides

A T-account is a quick sketch of one account: the name on top, debits on the left, credits on the right. Here is a cash T-account after a few transactions (illustrative figures):

Cash: debits (in)	Cash: credits (out)
Owner investment $8,000	Equipment $3,000
Bank loan $5,000	Wages $1,200
Client payment $2,500
Total $15,500	Total $4,200

Balance: $15,500 − $4,200 = $11,300 debit. Sketching T-accounts on paper is still the fastest way to reason through an unfamiliar transaction before you enter it in software.

Worked example: a startup's first six transactions

Northfield Web Studio, a fictional business, starts trading. Each transaction below is shown as a journal entry, followed by the accounting equation after it. All figures are illustrative.

#	Transaction	Debit	Credit	Amount
1	Owner invests cash	Cash	Owner's capital	$8,000
2	Takes a bank loan	Cash	Loan payable	$5,000
3	Buys equipment for cash	Equipment	Cash	$3,000
4	Invoices a client for a website	Accounts receivable	Service revenue	$2,500
5	Pays a contractor's wages	Wages expense	Cash	$1,200
6	Client pays the invoice	Cash	Accounts receivable	$2,500

The equation after each step

After #	Assets	Liabilities	Equity	Check
1	Cash $8,000 = $8,000	$0	$8,000	$8,000 = $0 + $8,000
2	Cash $13,000 = $13,000	$5,000	$8,000	$13,000 = $5,000 + $8,000
3	Cash $10,000 + equipment $3,000 = $13,000	$5,000	$8,000	$13,000 = $5,000 + $8,000
4	Cash $10,000 + AR $2,500 + equipment $3,000 = $15,500	$5,000	$10,500	$15,500 = $5,000 + $10,500
5	Cash $8,800 + AR $2,500 + equipment $3,000 = $14,300	$5,000	$9,300	$14,300 = $5,000 + $9,300
6	Cash $11,300 + AR $0 + equipment $3,000 = $14,300	$5,000	$9,300	$14,300 = $5,000 + $9,300

Notice what each step teaches:

• Step 3 swaps one asset for another. Total assets do not change.
• Step 4 raises equity through revenue ($8,000 + $2,500 = $10,500) even though no cash has arrived. That is accrual accounting at work; compare it with the cash method in cash vs accrual accounting.
• Step 5 lowers equity through an expense ($10,500 − $1,200 = $9,300).
• Step 6 converts a receivable into cash. Equity does not change, because the revenue was already recorded.

Total debits across the six entries: $8,000 + $5,000 + $3,000 + $2,500 + $1,200 + $2,500 = $22,200. Total credits are the same $22,200. Profit so far is $2,500 − $1,200 = $1,300, which is exactly the growth in equity beyond the owner's investment ($9,300 − $8,000 = $1,300).

Recording each line is covered in more depth in our journal entry examples, and the next stages, posting to the ledger accounts and checking totals with a trial balance, follow naturally. The resulting asset, liability and equity figures form the small business balance sheet.

How double-entry bookkeeping catches errors

The built-in check is the main practical benefit of the system. Because every entry must balance, a whole class of mistakes shows up immediately:

• One-sided entries. If you record a $500 payment to cash but forget to reduce receivables, total debits exceed total credits by $500.
• Typing errors on one side. Entering $1,250 as a debit and $1,520 as a credit leaves a $270 gap, which divides evenly by 9, a classic sign of transposed digits.
• Balances that make no sense. A credit balance in an expense account, or a debit balance in a loan account, flags a posting to the wrong side.
• Missing money. Because cash is tracked as an account, the ledger balance can be reconciled to the bank statement, and any difference points to something unrecorded.

It is not foolproof. An entry posted to the wrong account, or left out entirely, still balances. That is why double-entry bookkeeping is paired with monthly reconciliations and a quick review of each account, rather than relied on alone. Still, compared with a single-entry cash book, where an omitted or doubled transaction can go unnoticed for months, the double-entry method gives you far more confidence that the reports reflect what actually happened.

How to start using double entry

1. Set up a chart of accounts. Keep it short: cash, receivables, equipment, payables, sales tax payable, loan, owner's capital, owner's draws, revenue and your main expense categories.
2. Enter opening balances. Record what the business owns and owes on your start date, with the difference going to owner's capital.
3. Record invoices as you issue them. Debit receivables, credit revenue and sales tax payable. Issuing invoices from consistent invoice templates makes this easier, because every document shows the same fields in the same place.
4. Record bills as they arrive. Debit the expense or asset, credit payables. The two sides of trade credit are explained in accounts payable vs accounts receivable.
5. Record payments. Money in reduces receivables; money out reduces payables or hits an expense directly.
6. Reconcile and review monthly. Match cash to the bank and confirm debits equal credits.

Common mistakes

• Thinking "debit" means "bad" or "money out". It just means left side.
• Recording only one side. Spreadsheets allow it; the books will not balance.
• Treating owner's draws as an expense. Draws reduce equity directly and do not belong on the P&L.
• Treating loan repayments as expenses. Only the interest is an expense; principal reduces the liability.
• Booking customer payments as revenue when the invoice was already recorded. That counts the sale twice.
• Forgetting contra accounts. Accumulated depreciation is a credit balance linked to an asset.

Double-entry bookkeeping checklist for beginners

• I can state the accounting equation and explain each part.
• I know which account types increase with debits and which with credits.
• Every entry I record has equal debits and credits.
• Sales tax collected goes to a liability account.
• Owner's draws and loan principal are kept out of expenses.
• Cash is reconciled to the bank each month.
• A trial balance is run before reports are prepared.

Next step

Practice with your own last month: take five real transactions and sketch the T-accounts before you look at how your software recorded them. If you are weighing whether you need full accounting software at all, read our comparison of an invoice generator vs accounting software.