Reviewed and updated October 16, 2026
Rules and decisions to review
- Leaving out income because no tax form arrived: reporting rules can apply to cash, digital payments and other receipts.
- Treating all bank deposits as income or ignoring them all: identify sales, loans, transfers and owner contributions correctly.
- Claiming personal expenses as business costs: document business purpose and allocate mixed-use expenses.
- Guessing investment basis: obtain purchase and adjustment records before reporting a sale.
- Claiming a dependent without reviewing residency and support rules: household changes can affect eligibility.
- Assuming last year’s result is permanent: tax rules and personal circumstances change.
A practical example
A business bank statement can include both customer receipts and an owner’s transfer from personal savings. Coding every deposit as revenue overstates income; leaving out customer receipts understates it. Reconciliation resolves the difference.
Records to gather
Gather complete income records, reconciled books, receipts, investment basis, dependent information and a list of changes since last year.
Your next step
Reconcile the return to original records and ask about unexplained differences before signing. Keep a list of missing documents and correct any unsupported classification rather than repeating an assumption from last year.
Official sources
This guide provides general information. The rules depend on the tax year, jurisdiction and your circumstances. Ask our team which filing or planning steps apply to you.
