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
For each payment between the UK and Nigeria, keep the document that created the obligation (contract or invoice), the approval, the bank confirmation, the exchange rate and sterling value you recorded, and the payee's receipt, plus any Nigerian withholding tax receipt. HMRC requires a UK company to keep accounting records for 6 years from the end of the financial year they relate to, and Nigeria's Tax Administration Act 2025 requires six years after the year of assessment.
An audit trail is the chain that lets someone who was not there follow a payment from the reason it was made to the place it ended up. Cross-border payments break that chain more often than domestic ones: invoices arrive by WhatsApp, the rate is agreed on a call, the payee is paid in naira while the books are in pounds, and a Nigerian customer deducts tax before paying. This guide sets out what to keep for each transaction and why.
What the law in each country asks for
GOV.UK's guidance on company and accounting records says a limited company must record all money received and spent, its assets, the debts it owes and is owed, and keep supporting documents such as receipts, invoices and bank statements. Those records must be kept for 6 years from the end of the last financial year they relate to, and longer in some cases, for example where a transaction covers more than one accounting period or HMRC has opened a compliance check. HMRC can fine a company £3,000, or a director can be disqualified, for not keeping accounting records.
On the Nigerian side, section 31 of the Nigeria Tax Administration Act 2025 requires every person, including exempt ones, to keep books and records with enough information to work out tax liability, in English, for not less than six years after the year of assessment. A Nigerian subsidiary is caught directly, and the UK parent will need the same papers to support its own accounts.
The document set for one payment
| Stage | Document | Why it matters |
|---|---|---|
| Reason | Contract, purchase order or signed quote | Shows the payment was for the business |
| Demand | Supplier invoice, with Tax ID and CAC number if Nigerian | Supports the cost; Nigerian VAT invoices must carry set details |
| Approval | Who approved, when and up to what amount | Proves the control worked |
| Payment | Bank or app confirmation with amount, currency and date | Links the invoice to cash |
| Conversion | Rate used and resulting sterling value | Needed for UK books and, for VAT, a consistent method |
| Receipt | Payee's receipt or acknowledgement | Closes the loop; required by law for Lagos rent |
| Tax | Withholding tax receipt where tax was deducted | The recipient's evidence to claim a credit |
Two items are often missing. The first is the rate. For VAT, Notice 700 section 7.6 lets you use the UK market selling rate at the time of supply, HMRC's period rates if you adopt them, or a commercial rate HMRC agrees to in writing. Record which one you used. The second is the withholding tax receipt. PwC's summary of Nigeria's 2024 withholding regulations notes that the payer issues a receipt and the recipient claims credit on presenting it, so a receipt that never arrives is tax the recipient cannot use.
Example: one Lagos supplier payment
Example only. A UK company's Nigerian subsidiary pays a Lagos events firm ₦4,000,000 for a product launch. The file holds the signed quote, the invoice showing the firm's Tax ID, an approval note from the UK finance director, the transfer confirmation, a note of the rate used to put the cost into the group's sterling books, the firm's receipt, and the withholding tax receipt the subsidiary issued for the 2% it deducted on other services, ₦80,000. An auditor can follow every step without asking anyone.
How to file it so it survives
- One reference per payment. Put the same reference on the invoice, the payment narrative and the receipt.
- Store by financial year. Retention runs from the end of the year the record relates to, so a folder per year makes deletion dates obvious.
- Capture paper early. Photograph or scan Nigerian paper receipts on the day; see digitising Nigerian paper receipts for HMRC.
- Keep the VAT link. Notice 700/21 calls the VAT account the audit trail between business records and the VAT return; if you are VAT-registered, Making Tax Digital requires certain records to be held in compatible software.
- Do not rely on chat apps. Export anything agreed on WhatsApp into the file.
Where trails usually break
- Payments split across several transfers with no shared reference.
- Cash paid in Nigeria with no receipt; Lagos tenancy law, for example, makes a rent receipt obligatory.
- Rates noted in a spreadsheet nobody can find later.
- A customer's short payment recorded as a discount instead of withholding tax.
- Staff leaving with the only copy in a personal inbox.
For matching payments to invoices across currencies, see AI agents for bank reconciliation across GBP and NGN, and for how long each record must be kept, HMRC record-keeping rules for foreign transactions.
Where Pryme fits
Each payment from a Pryme Business Account carries its amount, currency and date, and any customer can generate a regular or a verifiable receipt or statement through our partner VerifyDoc.ai; anyone can check that a verifiable one is genuine and unaltered. The Finance agent can gather invoices, approvals and receipts against each payment for review.
Questions people ask
How long must a UK company keep records of payments to Nigeria?
GOV.UK says 6 years from the end of the last company financial year they relate to, longer in cases such as multi-period transactions or an open HMRC check.
How long must a Nigerian company keep tax records?
Section 31 of the Nigeria Tax Administration Act 2025 says not less than six years after the year of assessment, kept in English.
Do I need to record the exchange rate I used?
Yes. For VAT, Notice 700 s.7.6 sets which rates are acceptable and expects a consistent method; your accounts need the sterling value too.
What is a WHT receipt and why keep it?
The receipt a Nigerian payer issues for withholding tax it deducted. PwC's summary of the 2024 regulations says the recipient claims credit on presenting it.
Sources
- GOV.UK: Running a limited company, company and accounting records · accessed Oct 2026
- Nigeria Tax Administration Act 2025 (gazette copy) · accessed Oct 2026
- HMRC VAT guide (Notice 700), section 7.6 foreign currency · accessed Oct 2026
- HMRC Record keeping (VAT Notice 700/21), updated 18 Mar 2024 · accessed Oct 2026
- PwC Nigeria: Highlights of the Deduction at Source (Withholding) Regulations 2024 · 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.