Which exchange rate should you record for a purchase in another currency?

Record the amount your account was actually charged, in your account's currency, next to the price in the currency you paid. The rate between those two numbers is the one that belongs in your records, and a rate from a converter or a news site is only an estimate until the charge posts.

Why is there more than one rate?#Link to this section

Pay for a €24 dinner with a dollar card and up to four numbers are involved. They rarely agree.

1. A published reference rate. The European Central Bank publishes euro reference rates around 16:00 CET every working day, and says they are "published for information purposes only. Using the rates for transaction purposes is strongly discouraged."
2. The card network's rate. Bank of America's foreign exchange FAQ says the rate for a card purchase abroad is set by Visa or Mastercard, and is "either the wholesale market rate or a government-mandated rate on the day before the date the transaction is processed. The processing date may differ from the date of the transaction."
3. Your bank's fee. CIBC's page on foreign currency card fees says "It's common for a credit card company to charge a foreign currency conversion fee between 1% and 3% of the transaction amount."
4. The amount that posts. The same CIBC page warns that "The pending transaction amount may be different than the final posted amount."

Only the fourth number is money that left your account.

Which one do you write down?#Link to this section

The posted amount, in your account's currency.

It already includes the rate the network used on the day the charge was processed, and any fee that was added into the charge. It is also the number your balance and your statement show, so recording it is what keeps the two in agreement.

Keep the original price as well, in the currency you paid. That is what the receipt says, and it is what you will look for later.

The rate for your records is then one number divided by the other. With made-up figures:

• The dinner: €24.00
• Posted to your dollar card: $26.90
• The rate for your records: 26.90 ÷ 24.00, which is about 1.1208 dollars per euro

What if the charge is still pending?#Link to this section

Record an estimate now and correct it when the charge posts.

Today's rate from any converter is a fine placeholder. When the posted amount appears, change the entry to match it. The difference is usually small, but it is the difference between a balance that matches your statement and one that drifts away from it.

Should the fee be its own entry?#Link to this section

Do what your statement does.

• The fee is inside the posted amount: it is part of what the dinner cost. Record one entry.
• Your statement shows the fee as its own line: record it as its own expense, for example in a "Bank fees" category. After a year, that category tells you what spending abroad cost you in fees alone.

What about the offer to pay in your own currency?#Link to this section

Some card terminals and cash machines abroad offer to convert the price for you, so that the charge arrives already in your home currency.

In the EU, the law makes that offer show its price. Regulation (EU) 2019/518 requires providers, including "parties providing currency conversion services at an automated teller machine (ATM) or at the point of sale", to "express the total currency conversion charges as a percentage mark-up over the latest available euro foreign exchange reference rates issued by the European Central Bank". That mark-up "shall be disclosed to the payer prior to the initiation of the payment transaction", so you can compare it before you choose.

Whichever you choose, the rule for your records stays the same: record what your account was charged.

Why does a refund not cancel the purchase exactly?#Link to this section

Because the refund is converted again, on a different day.

CIBC's page, for example, says a refund is converted "using the foreign exchange rate on the return date, which may differ from the exchange rate that was in effect on the purchase date", and that "A foreign currency conversion fee will also apply to the refund."

So record the refund as its own entry, at the amount that posts. Do not edit the original purchase to make the two cancel out. The small gap that remains is real: it is what the round trip cost you.

What about cash, and money moved between your own accounts?#Link to this section

The same rule, with different paperwork.

• Cash you exchanged. Your rate is what you received divided by what you paid, from the exchange receipt. Use that rate for the spending the cash paid for, not the rate on the day of each purchase.
• A transfer between your own accounts in two currencies. Your rate is the amount that arrived divided by the amount that left. Any fee the transfer service took is inside that gap.

Why store the rate with each entry at all?#Link to this section

Because the alternative rewrites your history.

An app that converts old entries at today's rate changes the value of last year's dinner every day, and every total that includes it moves with it. What a multi-currency net worth tracker has to get right covers that problem in full. Storing the rate you actually paid, with the entry, is what keeps a finished purchase finished.

How Hundo handles this#Link to this section

• A transaction can be in a currency its account does not hold. When the two currencies differ, the form asks for an exchange rate.
• The rate is filled in for you, and you can type over it. Replace it with the rate from your statement once the charge posts. The swap button lets you enter it either way round, "1 EUR = ? USD" or "1 USD = ? EUR", whichever is easier to work out.
• The rate is stored with the transaction. The account balance moves by the converted amount, and the stored rate does not change when the market does.
• Transfers work the same way. A transfer between two accounts in different currencies takes a rate too.

All of this is part of the free tracker, in 166 currencies, with nothing capped.

To see the arithmetic before you sign up for anything, two free calculators run in your browser:

• Add up a net worth across several currencies, at today's rates.
• See how much of an investment's return was the exchange rate.

Common questions#Link to this section

Should you use the mid-market rate or your bank's rate?#Link to this section

For your records, use neither on its own: use what your account was charged. A published rate is still useful, because comparing it with your effective rate shows what the conversion cost you.

Do you record the foreign transaction fee separately?#Link to this section

Only if your statement shows it as a separate line. If the fee is inside the posted amount, it is part of the purchase.

Which rate do you use for a purchase that has not posted yet?#Link to this section

Today's rate, as a placeholder. Correct the entry to the posted amount when it appears.

Does any of this matter for small purchases?#Link to this section

For one coffee, no. Over a year of spending abroad, the gap between published rates and what you were charged is what converting cost you, and you only see it if you record the charged amounts.

Checked 15 September 2026 against the ECB, Bank of America, CIBC and EUR-Lex pages linked above. Card terms differ between banks and change over time; your own card agreement is the authority for your card.