Most landlords don't lose money on tax season because they did something wrong — they lose money because they didn't track something right. Missing receipts turn into missed deductions, and a T776 filled out from memory in March is never as complete as one built from a running record kept all year.

Here's the structure we use across our own 19 doors, one folder per property, updated monthly instead of reconstructed annually.

Track these every month, per property

Rent received, and separately, any security or damage deposits — deposits are not income and shouldn't be mixed into the same bucket as rent.

Mortgage interest (the interest portion only, not principal), property tax, and insurance premiums.

Repairs and maintenance, condo or HOA fees, utilities you pay as the landlord, and any professional fees — accounting, legal, or property management.

Mileage or travel between properties, if you self-manage and drive to units for showings, repairs, or inspections.

Repairs vs. improvements: the distinction that actually matters

This is where most self-managing landlords get tripped up. A repair that restores something to its original condition — patching drywall, fixing a leaking faucet — is generally a current expense, deductible in the year you paid it. An improvement that adds value or extends the life of the property beyond its original condition — a new roof, a renovated kitchen — is typically a capital expense, depreciated over time through Capital Cost Allowance instead of deducted all at once.

The line between the two isn't always obvious, and getting it wrong in either direction either costs you a deduction now or creates a problem later. This is genuinely worth a conversation with an accountant who works with rental property, not a guess.

What we keep at year-end

One file per property with every receipt tagged to a category above, a running log of rent and deposits received, and a short note on anything unusual — a unit vacant for a stretch, a major repair, a tenant turnover. None of it is complicated on its own. It just has to happen monthly, not in April.