Periods are how you slice time
A business operates continuously, but its reports cannot. Dividing activity into periods lets you ask whether this month was better than last month, or this year better than last. Most businesses use several at once: a monthly close for management, a quarterly review for planning and a full year for tax and lenders.
Each period starts the day after the previous one ends, so every transaction belongs to exactly one period. That is why dates matter as much as amounts in your records. If a sale is dated in the wrong period, two sets of statements are wrong rather than one.
How it differs from the fiscal period and tax year
“Accounting period” is the general term. The CRA uses fiscal period for the annual reporting window used on a tax return. For an existing business it is usually twelve months, and it can be shorter when a business starts or stops. Self-employed individuals generally report on a December 31 year-end, although some eligible individuals can use another year-end and reconcile income on a separate form.
A corporation’s tax year is its fiscal period, which cannot be longer than 53 weeks. A new corporation can generally choose its year-end, and later years begin the day after the previous one ends. The T2 return is due six months after the period ends. For the closing date itself, see fiscal year-end.
An illustrative example
Suppose a corporation has a June 30 year-end and closes its books monthly. A customer is invoiced $5,000 on June 28 for work completed that week and pays on July 10. The invoice belongs in the period ending June 30, with a receivable at that date, even though the cash arrives in the next period. The figures are illustrative only.
If the same business compared a June that included that invoice with a July that did not, July would look weaker for reasons unrelated to performance. Using the same period lengths and the same basis each time keeps comparisons honest.
Mistakes and what to discuss with your accountant
Common problems include comparing periods of different lengths, leaving a period open while late bills trickle in, and treating a software reporting range as if it changed the tax year. Changing a corporation’s year-end generally needs the CRA’s approval unless a specific exception applies.
Ask your accountant which period lengths suit your decisions, what cutoff date records are needed after each close, and whether a first or final period will be shorter than twelve months. Bring invoices, supplier bills and bank statements dated either side of each period end.
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.
- Accounting for your earningsCanada Revenue Agency
- Determining your corporation's tax yearCanada Revenue Agency
- CRA: Guide T4002, fiscal period and reporting incomeCanada 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.