myCostBase brings your adjusted cost base, capital gains, and supporting transaction history together in one reviewable ledger. Import your brokerage records, review your calculations, and prepare the figures for your tax software or preparer.
Supported investments and calculations
Track securities, ETFs, and single-leg options transactions in taxable brokerage accounts. Supported option events include buy/write, exercise, assignment, and expiry. Each leg of a spread, straddle, or collar has its own transaction history and calculations; strategy-level grouping is not currently available.
Pool ACB across brokerages, convert foreign-currency transactions using Bank of Canada exchange rates, and apply ETF return-of-capital and DRIP adjustments. The Methodology page explains the calculation rules.
Cryptocurrency requires a separate record-keeping and calculation workflow; the current ledger covers securities, ETFs, and options.
Bring your brokerage history together
Load transaction history through CSV imports or manual entry. You choose the files and records to add, without sharing your brokerage login. See Supported Brokers for available import formats. Direct brokerage API sync is not currently available.
Prepare your figures for filing
Use the ACB ledger and capital gains detail to prepare information for filing software such as TurboTax or StudioTax, or to share with your preparer. Your return is filed through that software or your preparer; myCostBase supplies the supporting calculations and records.
Record corporate actions
Stock splits and returns of capital are supported. For mergers, spin-offs, and rights offerings, establish the correct tax treatment and record reviewed manual ACB adjustments. These less common events are not currently automated.
Practical workflows for your records
Complex corporate actions: Download the issuer’s Canadian tax explanation and record the effective date, securities involved, quantities, and any cash component. Establish the correct treatment before entering manual adjustments. For an allocation, keep a worksheet showing the cost removed from one holding and assigned to another, then reconcile both quantities and total cost. The spin-off workflow explains the evidence and election questions. Do not force an uncertain event into an ordinary buy or sale.
Importing brokerage history: Export transaction history periodically, keep the original file, and preview its mapping. Use non-overlapping periods where practical and review duplicates when periods overlap. Check closing quantities after each batch. Never send your brokerage or CRA password to support; an export and a description of the issue are the relevant inputs.
Moving your figures into filing software: Finish the ledger and reconcile dispositions, then transfer the reviewed information into your filing software or send it to your preparer. Check that a T5008 imported by the filing software does not duplicate a manually entered sale. The Schedule 3 walkthrough explains that handoff.
Keeping cryptocurrency records: Keep those records outside this securities ledger and use a suitable separate process or professional review. Renaming a crypto transaction as a stock trade does not make the resulting calculation supported.
Independent option legs: Preserve each contract’s opening and closing history and review assignment, exercise, and expiry events. If you need strategy-level reporting or a relationship between several legs, maintain a separate reviewed schedule. Do not infer a combined strategy result from a single leg’s gain.
Portfolio analytics: Use brokerage or separate portfolio reports for performance, asset allocation, or market-value analysis. ACB is a tax-cost record; it does not measure investment performance by itself.
Review unusual events before filing
Keep the source document, the import warning or unclear ledger entry, and your proposed explanation together. Identify which security and reporting period are affected. If the available fields cannot faithfully represent a reviewed adjustment, contact support before using a workaround. For uncertain tax treatment, consult a qualified professional; product support cannot establish the legal treatment of a reorganization or ownership change.