Cross-Border Bookkeeping: Currency, Two Sets of Rules, and the Books That Have to Satisfy the IRS and the CRA

Cross-border books are one set of records read by two tax authorities, and the reconciliations are the work. The functional currency — which dollar the books are in: a Canadian corporation keeps its books in Canadian dollars (the default for Canadian tax — though a Canadian-resident corporation, other than an investment, mortgage investment, or mutual fund corporation, whose primary currency for its financial-reporting books is a qualifying currency — the U.S. dollar, euro, pound sterling, yen, or Australian dollar — may elect under section 261 to compute its Canadian tax in that currency, filing Form T1296 within 60 days after the first day of the first year; the election can be revoked, but the corporation can never elect again); a U.S. company keeps its books in U.S. dollars; a U.S. company with a Canadian branch or a Canadian qualified business unit keeps that unit's books in Canadian dollars and translates for the U.S. return (the section 987 rules for branches — final regulations published in December 2024 apply to tax years beginning after December 31, 2024, with transition rules for pre-2025 gain or loss that Notice 2025-72 said will be modified); a U.S. person reporting a Canadian corporation's results on Form 5471 translates its Canadian-dollar earnings and profits and income inclusions at the average rate for the year (section 989(b)), accrued Canadian income taxes generally at the average rate for the year they relate to (section 986(a)), and actual distributions at the spot rate on the day paid. The exchange rates — which rate for what: Canada accepts the Bank of Canada's daily rate on the transaction date or, for recurring items, the annual average rate where rates don't fluctuate significantly (section 261's relevant spot rate, with the CRA also accepting another widely available, verifiable rate used consistently — Income Tax Folio S5-F4-C1); the United States uses the spot rate for specific transactions (the IRS accepts any reasonable source consistently used) and the yearly average rate for many items (published on irs.gov each year); a capital transaction (the purchase and sale of property — the ACB guide's point) uses the rate on each transaction's date, which is why the same property's gain differs in each country's currency; foreign exchange gains and losses on receivables, payables, and foreign-currency bank accounts are income or loss when realized (Canada — business income or loss on a business's receivables, payables, and operating accounts, or a capital gain or loss on capital transactions, with an individual ignoring the first C$200 of net capital-account foreign exchange gain or loss each year under section 39(1.1); the United States — ordinary income or loss under section 988 on business transactions, with an individual's personal-transaction gains of US$200 or less per transaction exempt under section 988(e)). The book-to-tax differences — two sets: Canadian tax starts from the financial statements and adjusts for capital cost allowance instead of book depreciation (the classes and rates — the T776 guide's CCA), the 50 percent meals limitation, the non-deductible items, and the reserves; U.S. tax starts from the same statements and adjusts for MACRS, section 179, and bonus depreciation (the Set 7 depreciation explainers), the 50 percent meals limitation (with the business-meal rules), the section 163(j) interest limitation, and the U.S.-specific items; the same asset therefore has a book value, a Canadian undepreciated capital cost, and a U.S. adjusted basis — three numbers in three schedules, maintained from the same purchase record. The year-end: a Canadian corporation can choose any fiscal year-end (non-calendar is common); a U.S. C corporation can too, but a U.S. S corporation and most partnerships use the calendar year; a Canadian parent with a U.S. subsidiary often aligns the subsidiary's year-end with the parent's (the U.S. C corporation can elect it) for consolidated financial statements; a U.S.-resident individual reports a Canadian corporation's results (Form 5471) for the corporation's fiscal year ending within the individual's tax year. The intercompany accounts — the reconciliation that both returns read: a group with entities in both countries records intercompany charges (management fees — the management fees guide; intercompany loans — the intercompany loans guide; sales of goods; recharged costs) in both entities' books, in each entity's currency, at the same rate, reconciled monthly so that each side's receivable equals the other's payable; the reconciled amounts feed Form 5472 (the U.S. side) and T106 (the Canadian side), and the transfer pricing documentation; unreconciled intercompany balances are the single most common cross-border bookkeeping failure and the first thing an examiner in either country asks about. The sales taxes — two systems: the U.S. entity's state sales and use taxes (by state, by nexus — the Florida service sales tax guide for Florida) and the Canadian entity's GST/HST and provincial sales taxes (with input tax credits — a value-added system — versus the U.S. retail sales tax with no credits), recorded as liabilities and recoverable assets in each entity's books — never income or expense except where unrecoverable. Payroll — two systems: the U.S. payroll (federal, state, FICA, FUTA, state unemployment) and the Canadian payroll (federal and provincial income tax, CPP or QPP, EI, provincial health taxes — the Quebec cross-border guide's extras), each with its own year-end slips (W-2s and T4s), and the cross-border employees' coverage certificates and recharges (the stock options guide's workday records feeding both). The software: a multi-entity, multi-currency accounting system (multi-currency is standard in the major cloud ledgers; multi-entity consolidation usually needs a higher-tier platform or a consolidation tool) with each entity in its own currency, the intercompany accounts mapped, the exchange rates loaded daily, and the tax schedules (CCA and MACRS) maintained in fixed asset modules or separate tax software; consolidation for the group's financial statements eliminates the intercompany balances. The year-end close — both returns' inputs: the trial balance per entity in its currency; the intercompany reconciliation; the fixed asset roll-forward with book, CCA, and U.S. tax columns; the foreign exchange gains and losses realized; the sales tax and payroll reconciliations; the related-party transactions schedule (5472 and T106); and the shareholder accounts (loans to and from owners — the intercompany loans guide's section 15(2) clock). The errors: one entity's books in the wrong currency; average rates used for capital transactions; the CCA schedule and the MACRS schedule out of sync with the asset register; intercompany balances that don't agree; GST/HST recorded as revenue; the U.S. subsidiary's year-end not aligned with the parent's consolidation; and no foreign exchange gain or loss recognized on a U.S.-dollar receivable collected after a rate move.

Key takeaways

• Each entity keeps its books in its functional currency — Canadian dollars for a Canadian corporation (a functional currency election is possible for some), U.S. dollars for a U.S. company — and translates for the other country's filings.
• Exchange rates by purpose: transaction-date rates for capital transactions; average rates for recurring income items where permitted; realized foreign exchange gains and losses recognized on receivables, payables, and foreign-currency accounts.
• One asset, three numbers: book value, Canadian undepreciated capital cost, and U.S. adjusted basis — maintained in parallel schedules from the same purchase record.
• Intercompany accounts must agree monthly in both entities' books — they feed Forms 5472 and T106 and the transfer pricing documentation, and they're an examiner's first question.
• Sales taxes and payroll run in two systems; GST/HST and state sales taxes are liabilities or recoverable assets, never income.
• The year-end close produces both returns' inputs — per-entity trial balances, the intercompany reconciliation, the fixed asset roll-forward, foreign exchange, sales tax, payroll, and related-party schedules.

The cross-border bookkeeping close

Per entity: trial balance in its functional currency. Exchange rates loaded; capital transactions at transaction-date rates. Foreign exchange gains and losses realized. Intercompany reconciliation (agree to the cent); Forms 5472 and T106 schedules. Fixed asset roll-forward: book, CCA, U.S. tax. Sales tax reconciliations (state; GST/HST and provincial). Payroll reconciliations (W-2s; T4s). Shareholder loan accounts and their clocks. Year-ends aligned. The intercompany reconciliation is the step that makes everything else reconcile.

Worked example

A Vancouver parent (Canadian-dollar books, March 31 year-end) and its Florida subsidiary (U.S.-dollar books — the subsidiary, a C corporation, elected a March 31 fiscal year to match): each month, the parent invoices the subsidiary its management fee in U.S. dollars (recorded by the parent in Canadian dollars at the invoice date's Bank of Canada rate, with the foreign exchange gain or loss on collection recognized), the subsidiary's payable and the parent's receivable reconcile in U.S. dollars, and the intercompany loan's interest accrues on both sides. At year-end: the fixed asset register carries the subsidiary's warehouse racking at its book value, its U.S. adjusted basis (fully expensed under the 100 percent bonus depreciation available for property acquired after January 19, 2025), and no Canadian CCA (the subsidiary isn't a Canadian taxpayer; the parent's consolidation uses the book value); the parent's own equipment carries book value and CCA; the related-party schedule feeds the subsidiary's Form 5472 and the parent's T106; the subsidiary's Florida sales tax and the parent's GST/HST are reconciled separately; the W-2s and T4s are issued; and the consolidated statements eliminate the intercompany balances to zero. A peer group whose two entities recorded the same management fee at different exchange rates spent its year-end chasing a C$38,000 intercompany difference that both tax returns had to explain.

Official sources

The IRS explains: “Corporations file Form 5472 to provide information required under sections 6038A and 6038C when reportable transactions occur with a foreign or domestic related party.” — Internal Revenue Service, About Form 5472, Information Return of a 25% Foreign-Owned U.S. Corporation or a Foreign Corporation Engaged in a U.S. Trade or Business, https://www.irs.gov/forms-pubs/about-form-5472

IRS Publication 597 explains: “This publication provides information on the income tax treaty between the United States and Canada. It discusses a number of treaty provisions that most often apply to U.S. citizens or residents who may be liable for Canadian tax.” — Internal Revenue Service, Publication 597 (10/2015), Information on the United States–Canada Income Tax Treaty, https://www.irs.gov/publications/p597

Practitioner note

Cross-border books are one set of records read by two tax systems, and the work is in the reconciliations: each entity in its own currency, capital transactions at their own dates' rates, three numbers for every asset, and intercompany accounts that agree to the cent in both sets of books before Forms 5472 and T106 are prepared. Our desks run a monthly close that produces both returns' inputs at once — the per-entity trial balances, the intercompany reconciliation, the fixed asset roll-forward with book, CCA, and U.S. tax columns, and both countries' sales tax and payroll reconciliations — because an unreconciled intercompany balance is the first question an examiner in either country asks.

See also: For related guidance, see cross-border bookkeeping for Canada–U.S. businesses and currency conversion and exchange rates on cross-border tax returns; and browse every cross-border tax topic guide, organized by situation.

Next step

Fairlight Accounting is a cross-border accounting and tax practice with a U.S. Tax Desk and a Canadian Tax Desk. Our U.S. Tax Desk and Canadian Tax Desk handle cross-border bookkeeping and close — functional currency setup, exchange rate policies, foreign exchange gain and loss recognition, parallel CCA and U.S. depreciation schedules, monthly intercompany reconciliations, related-party reporting for Forms 5472 and T106, dual sales tax and payroll reconciliations, and year-end alignment for consolidated groups. See pricing or book a call.