Preparation resource. Editorial review: November 3, 2026. This guide helps organize records and questions; it does not determine your tax position. Use the agency instructions for the relevant year and obtain advice for your circumstances.
Records to organize
Prepare the records that relate to your situation and keep the original supporting statements. Use the same filing year or clearly labelled periods so the reviewer can follow the history.
- Current income and expense records
- Prior returns and loss-balance information
- Business activity, ownership and relevant CRA decisions
How to use these records
Identify the taxpayer and loss category and retain prior assessments and schedules. Carryover treatment depends on the kind of loss and applicable period. A negative business ledger balance is not proof that the amount can offset every source of current income.
The question to resolve before filing
What kind of loss is involved, and which use or carryover conditions apply?
Start with the facts you can support. Identify missing statements, corrections and earlier filings instead of filling a gap with an estimate that has not been discussed. Tell the team which countries, tax years and agencies are involved so the engagement can cover the right work.
A mistake to avoid
Do not assume every negative business result can immediately offset any other income.
A clear handoff to your preparer
- Label the evidence. Keep each record with its relevant year, account or activity.
- List open questions. Share missing information and anything that differs from the prior return.
- Confirm the scope. Ask which returns, disclosures and follow-up work are included before preparation begins.
Do not enter identity numbers, account numbers, verification codes or tax-document copies in a public enquiry. Use your private client portal for requested records after onboarding.
Official starting points
Use the current agency guidance and the instructions for the applicable filing year. A source link is not confirmation that a particular rule, election or claim applies to your circumstances.