Two sides of every transaction
Every transaction has two effects. When a business buys a laptop with cash, it gains an asset and loses cash. When a customer pays an invoice, cash goes up and the amount owed by customers goes down. Double-entry bookkeeping records both effects, so the books never show only half of what happened.
The structure rests on the accounting equation: assets equal liabilities plus equity. Each entry changes the accounts in a way that keeps that equation true. How each side is labelled is covered under debits and credits.
An illustrative example
Suppose a business borrows $10,000 from its bank. Cash increases by $10,000 and a loan liability increases by $10,000. Nothing is recorded as income, because the business now owes the money back. A system that only tracked money in and out might mistake the deposit for a sale.
If the business then spends $2,000 of that cash on equipment, cash falls by $2,000 and equipment rises by $2,000. The business holds the same total value in different forms. The numbers are round and ignore sales tax.
What the method catches and what it misses
Because the two sides must agree, an entry that is out of balance is usually rejected or flagged, and a trial balance can reveal a one-sided posting. This is a real strength compared with a simple list of income and expenses.
It has limits. An expense recorded in the wrong account still balances. So does a duplicated payment, or a personal purchase coded as a business cost. Balanced books show internal consistency, not accuracy, which is why reconciliations and supporting documents still matter.
Software, spreadsheets and the CRA
Most accounting software applies double-entry rules in the background, so you may never type a debit or credit yourself. A spreadsheet of income and expenses is a simpler single-entry approach and does not track what you own and owe. The CRA says it does not suggest any particular set of books, but your records must support the income and expenses you report and be clear and easy to read.
Ask your accountant whether your current setup produces a balance sheet as well as an income statement, who reviews manual entries, and how your records link back to receipts and statements. A move from a spreadsheet to double-entry software is easier when opening balances are agreed first.
Sources & editorial notes
Sources checked October 24, 2026. The examples are illustrative and provide general information. Discuss how the guidance applies to your circumstances with your accountant.
- Business recordsCanada Revenue Agency
- What are records, who has to keep them, and why it is importantCanada Revenue Agency
Rules and guidance can change. Use the current official source and confirm the treatment for your facts. To flag an error, contact Sora.