Every month you send an owner, a lender, or an accountant one figure for buildings on both sides of the border, as if it were an amount. A spreadsheet makes it by turning CAD and USD into a single total at a rate somebody typed in. It goes out a little different every month whether or not anything in a building changed.
Look at what that figure is. Rent from a building in Ontario and rent from a building in Arizona, added together after one of them was multiplied by a number that was true for one day, or for no day at all, because it was the rate a bank quoted once, or last month's rate nobody updated, or a round number that was close enough in the spring. The total has no unit. It is not Canadian dollars and it is not US dollars; it is a mixture, at a proportion that changes every time somebody edits one cell.
The cost is not the twenty minutes the spreadsheet takes. It is the owner who compares this month's figure with last month's and sees a building doing worse, when the only thing that moved was the rate. It is the lender who reads a coverage figure that drifts with the exchange rate and asks what happened. It is the accountant who receives the total at year end and has to unpick it into its two currencies before translating each of them again, properly, at the rate the tax authority accepts, and who bills for the unpicking. It is the fee conversation, the capital decision, and the keep-or-sell question, all argued from a number that is partly rent and partly currency, with no way to say which part is which.
And underneath it sits the quiet second set of books: the real amounts, in their real currencies, which live in your head, in two bank statements, and nowhere an owner can see.
Add a Canadian dollar to an American one and the total is a number, not an amount.
Give every account its currency and stop adding across the line. The Ontario building's rent posts to CAD accounts and the Arizona building's rent posts to USD accounts; each bank account reconciles against its own statement in its own currency; and the statement that goes to an owner has two sections, one per currency, each closing on its own net, with the currency code beside every figure. The owner with buildings in both sees two amounts and can check either of them. The owner with buildings in one never sees the other side. The accountant gets closed, reconciled totals in each currency and translates each of them once, at year end, at a published rate, with the rate written beside the result. The rate conversation moves from inside the figures to a line underneath them.
Scaalr puts a currency on every account, entry, and report: a rent charge posts to its lease's currency, each bank account reconciles in its own, and every statement shows one section per currency with the code beside every figure. The setup, the monthly routine, and the exchange rates the CRA and the IRS accept are in Managing Rental Properties in Both CAD and USD: One Ledger.
For the full setup, from the currency switch to the year-end translation, see: Managing Rental Properties in Both CAD and USD: One Ledger.
The first 5 units are free, then $0.99 a unit a month, and both currencies are on every plan.