After processing a return, the CRA issues a Notice of Assessment (NOA). It confirms the tax calculation, shows any changes, and contains important information for the coming year. It is available in CRA My Account (and by mail for those who have not chosen online mail).
The date of assessment, which starts the clock for objections and reassessments.
Key lines: total income, net income, taxable income, total payable, total credits, and the refund or balance owing.
An explanation of any changes the CRA made, and why.
RRSP deduction limit for the next year and unused RRSP contributions.
FHSA participation room.
Home Buyers' Plan and Lifelong Learning Plan repayment amounts.
Canada training credit limit.
Unused tuition amounts and net capital losses carried forward (sometimes shown on a separate statement).
Instalment requirements, if any.
A reassessment is issued when the CRA changes a previously assessed return, either at the taxpayer's request or after a review. It shows the new amounts and resets the objection deadline for the matters reassessed.
Normal reassessment period: three years from the date of the original NOA.
Extended by three years for certain matters such as loss carrybacks, foreign reporting (T1135) and transactions with non-arm's length non-residents.
Unlimited if there was misrepresentation from carelessness, neglect or wilful default, or if a waiver (Form T2029) was signed.
Unlimited for unreported dispositions of a principal residence.
Compare the NOA with the filed return.
If the CRA made an error or missed something, request an adjustment or file an objection.
Note the RRSP and FHSA room and carry-forwards for planning.