AI agents for business finance: what they can and can't do
What AI agents can do in bookkeeping, close, collections and compliance today, where a person must stay in charge, and how to judge a product.
The short answer
Most tax offices want each item converted at the rate on the day it was received or paid, and accept an average rate only where that is reasonable and used consistently. The IRS says to use the rate prevailing when you receive, pay or accrue the item and publishes no official rate; the CRA says to use the Bank of Canada rate for the day the amount arises; HMRC asks for amounts in sterling on SA106 but its notes do not prescribe a source.
The naira has moved sharply in recent years, so the rate you pick can change your declared income by a large margin. There is rarely a single required rate, but there are rules about the method, and inconsistency is what gets questioned.
United States: the rate when you receive it
The IRS page on foreign currency (updated May 2026) says amounts on a US return must be in US dollars, and that you generally use the exchange rate prevailing when you receive, pay or accrue the item. The IRS has no official rate; it lists sources such as banks, US embassies, the Treasury, the Federal Reserve and commercial sites, and says any posted rate used consistently is generally acceptable. Its yearly average rates table has no naira row, so for Nigerian income you choose and document a source.
For foreign tax credits, the Form 1116 instructions say foreign taxes paid are converted at the rate on the day they were paid.
Canada: the Bank of Canada rate for the day
The CRA's line 12100 guidance says foreign interest and dividends are reported in Canadian dollars using the Bank of Canada rate in effect when the amount arises. Its Income Tax Folio S5-F4-C1 adds detail:
- use the Bank of Canada rate for the day, or the closest preceding day if none was published;
- another source is acceptable only if it is widely available, verifiable, independent, market-recognised, used for financial statements and applied consistently;
- the CRA may accept an average rate for a period for practical reasons, but generally not when rates fluctuate significantly.
That last point matters for naira income: in a year of large swings, an annual average may not be accepted.
United Kingdom: sterling, with a documented method
HMRC's SA106 notes ask for foreign income in UK pounds before foreign tax, with the foreign tax in a separate column, but do not specify a rate source. HMRC publishes monthly and average exchange rates on the Trade Tariff service (average rates are published at 31 March and 31 December as the mean of 12 monthly rates), though their stated purpose is customs valuation. Whatever you use, apply it consistently and keep the workings.
Which naira rate?
The CBN publishes the Nigerian Foreign Exchange Market (NFEM) rate, which its rates page describes as the official exchange rate for the day. Nigerian employers use the CBN official rate for PAYE on foreign-currency pay (DLA Piper, August 2026). Using the official rate, or your own bank's actual conversion when money was converted, is easier to defend than an informal parallel-market quote.
Worked example: transaction dates versus an average
Example only, with invented rates to show the effect; these are not real or current rates. A London landlord receives three Lagos rent payments in one tax year.
| Payment | Naira | Illustrative rate | Sterling |
|---|---|---|---|
| April | ₦2,000,000 | ₦1,600 = £1 | £1,250.00 |
| August | ₦2,000,000 | ₦2,000 = £1 | £1,000.00 |
| January | ₦2,000,000 | ₦2,500 = £1 | £800.00 |
| Total | ₦6,000,000 | £3,050.00 |
If the landlord instead applied a single illustrative annual average of ₦2,000 = £1, the declared rent would be £3,000. The £50 difference is small here; in a year of steeper falls it can be much larger. The CRA's caution about averages in volatile years is the reason transaction-date conversion is the safer default.
Income held in dollars or pounds in Nigeria
Not all Nigerian income is in naira. Interest on a domiciliary account, or rent a tenant pays in dollars, is already in a foreign currency. For a US return, dollar income needs no conversion; for a UK or Canadian return you convert from dollars to sterling or Canadian dollars on the same principles, and there is no naira step to document. Mixed cases, where a tenant pays in naira and you later convert to dollars in Nigeria, are converted on the date the income was received, not the date you later moved it.
A method you can defend
- Pick one source per country (Bank of Canada for the CRA; a named, published source for the IRS and HMRC).
- Convert each receipt on its date, and each tax payment on its date.
- Record the date, naira amount, rate, source and result in a simple table.
- Use the same method every year; if you change it, note why.
- Keep bank statements showing each receipt; see records to keep.
Currency movements on naira assets can create their own gains or losses in some countries; see currency gains on naira assets.
Where Pryme fits
When you convert naira in the Pryme app with Swap, the rate is shown first and the fee on its own line before you approve, so each conversion leaves a dated record of the actual rate you got. Statements can be issued in verifiable form (receipts and statements).
Questions people ask
Can I use the yearly average rate for Nigerian income on my US return?
The IRS accepts any posted rate used consistently, but its own yearly average table has no naira row. The general rule is the rate when each item is received.
Which rate does the CRA want for naira income?
The Bank of Canada rate for the day the amount arises, or the closest preceding day. An average may be accepted for practical reasons, but generally not when rates swing significantly.
Does HMRC publish a naira exchange rate?
HMRC publishes monthly and average rates on the Trade Tariff service for customs purposes. Its SA106 notes do not prescribe a rate for income, so use a consistent, documented source.
Should I use the black market rate?
No. Use the CBN official rate or the rate your bank actually applied, which you can evidence.
Sources
- IRS: Foreign currency and currency exchange rates · accessed Oct 2026
- IRS: Instructions for Form 1116 · accessed Oct 2026
- CRA: Income Tax Folio S5-F4-C1, income tax reporting currency · accessed Oct 2026
- CRA: Line 12100, interest and other investment income · accessed Oct 2026
- UK Trade Tariff: Average exchange rates · accessed Oct 2026
- CBN: Exchange rates by currency (NFEM) · accessed Oct 2026
This article is general information, not financial, legal or tax advice. Products described are provided under the terms on this site and are subject to regulation and eligibility.