MyCostBase follows the actual sequence Canadian investors work through when adjusted cost base gets serious: define which accounts belong in the taxable pool, load transaction history, inspect the calculation trail, and produce the year-end output before filing. The goal is not speed at any cost. The goal is to make the ACB number defensible.
Define the tax owner and taxable account scope
Create the tax owner, add brokerage accounts, and mark each one as taxable or excluded. This step defines the ACB pool — non-registered accounts belong in, registered accounts (RRSP, TFSA, FHSA, RESP) stay out. Getting this right matters more than any other setup decision.
Import brokerage history or enter missing events manually
Upload broker CSVs or add transactions by hand for anything the import cannot express cleanly. Buys, sells, DRIP shares, return of capital adjustments, reinvested gains, broker-to-broker transfers, and corrections all land in one chronological ledger so the ACB history stays continuous.
Review the per-security ledger and resolve warnings
Open the security ledger to inspect share count, total ACB, ACB per share, Bank of Canada FX rates, and realized gains row by row. If a transfer cost basis is missing or an assumption needs review, the warning appears before you act on the result — not after.
Reconcile T5008 figures and export the capital gains package
Compare broker and T5008 values against MyCostBase, inspect the differences by security, and export gains summaries, disposition detail, and security-level audit trails for filing or accountant review. This is the step where a correct ACB ledger turns into numbers you can actually file.
Why this workflow fixes the actual adjusted cost base problem
Most ACB errors in Canada come from one of two sources: the transaction history is incomplete, or the final number cannot be traced back to the rows that produced it. MyCostBase addresses both.
The setup step makes taxable account scope explicit — so you know exactly which accounts belong in the pool before you import a single row. The import step brings all source history into one place. The ledger review step makes the calculation inspectable at the event level. The reconciliation step turns that ledger into the year-end outputs investors and accountants actually need.
MyCostBase does not replace your trading platform and it does not replace tax filing software. It fills the gap in between — where adjusted cost base is typically rebuilt by hand, often under deadline, often with incomplete records.
What to collect before you start
A smoother onboarding pass starts with the right records on hand:
- broker CSV exports for all taxable accounts you want to include;
- documentation for any broker-to-broker transfers, including original cost basis;
- ETF tax slips or issuer distribution details for return of capital and reinvested capital gain adjustments;
- any custom FX rate notes you already rely on.
Missing records for transfers and ETF adjustments are the most common reason an initial import produces warnings — not a product limitation, but a signal that the source history needs to be completed before the ledger can be trusted.
If you are ready to load history, start with Getting Started or jump to Importing Transactions.
Create a free account and load your first brokerage history →