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
Ask each main client for a signed letter on company letterhead that states its registered name and CAC number, how long you have worked for it, what it pays you, how often and in which currency, and whether the work is ongoing. Back it with your numbered invoices, the matching bank credits and any withholding tax receipts the client issued. Landlords, lenders and visa caseworkers trust documents that agree with each other.
Employees prove income with payslips their employer produces automatically. Freelancers have to ask for proof, and asking a busy founder in Lagos for "a reference" usually produces a two-line WhatsApp message that no letting agent will accept. The fix is to ask for something specific and make it easy to give.
When you will need one
- Renting: referencing firms often want evidence that income will continue (see proving freelance income to a UK landlord).
- Mortgages: an underwriter may ask about a client who supplies most of your income (UK mortgages for freelancers).
- Bank or account onboarding, where a compliance team asks about the source of incoming payments.
- Some visa and settlement applications that look at self-employed earnings; the route's own guidance says what it accepts.
What the client letter should contain
Send the client a short template and ask them to put it on their letterhead. A letter that answers these points usually needs no follow-up:
- Company's registered name, address and CAC registration number (RC or BN number).
- Your name, and the nature of the work (for example "brand design and social media management").
- Start date of the relationship and whether it is ongoing, fixed-term or ended.
- Fee basis: monthly retainer, per project or day rate, with the amount and currency.
- How payment is made (bank transfer to which account name) and how often.
- Whether the company deducts withholding tax from your fees.
- Name, title and direct email or phone of the signatory, with signature and date.
Ask that it is sent from an address on the company's own domain, not a free webmail account, and signed by someone senior enough to be credible (a director, finance lead or head of operations).
Make the paperwork agree
One letter on its own proves little. What persuades a reader is three sets of documents that tell the same story:
| Document | What it shows | Tip |
|---|---|---|
| Invoice | What you charged, when, in which currency | Number invoices in sequence and put the client's registered name on each |
| Bank statement | That the money arrived | Mark each credit with the invoice number it pays |
| Client letter | That the arrangement is real and continuing | Fee and frequency should match the invoices |
| WHT receipt | That the client paid Nigerian tax on your behalf | Explains why a credit is lower than the invoice |
Withholding tax receipts as evidence
Nigerian companies often deduct withholding tax before paying a supplier. PwC's Nigeria summary (reviewed 29 May 2026) lists 10% for non-residents on professional, consultancy, technical and management fees, as a final tax. Where tax is withheld, ask the client for the receipt or credit note. It does two jobs: it explains why a £1,000 invoice became a £900 credit, and it is the evidence you need if you claim relief in the UK. The Nigeria library explains how getting your WHT credit notes back works from the payer's side.
Asking without awkwardness
Most clients will help if the request is clear and quick. A short message works: say what the letter is for, attach the template, and give a date you need it by. For long-standing clients, ask once a year, around the time you file your return, so you always have a recent letter on file rather than chasing one under pressure. If a client is reluctant to state the fee, a letter confirming the relationship and its start date still helps, and the invoices and statements carry the figures.
Keep each letter with the invoices and statements for that year. For a mortgage, a lender reading HMRC's SA302 will see your total profit; client letters explain where it came from. Nationwide's published criteria, for example, rely on SA302s, tax year overviews or an accountant's certificate, with references as supporting evidence rather than the main test.
If a client has closed or stopped responding
Former clients are often hard to reach. Your own records then have to carry the weight: the signed contract, the invoices, the bank credits and any WHT receipts. Your filed Self Assessment return and SA302 show HMRC accepted the income. GOV.UK says SA302s are available for the last four years once you have filed, from 72 hours after you send the return.
Where Pryme fits
Pryme partners with VerifyDoc.ai, so any customer can generate a verifiable statement or receipt that anyone can check is genuine and unaltered (receipts and statements). With invoicing and a Business Account, invoices and the payments against them sit in one place, which makes the matching above simpler. For one-off proof of a particular payment, see receipts as proof of Nigerian client payments.
Questions people ask
What should a client reference letter include?
The company's registered name and CAC number, your role, start date, fee and frequency, payment method, whether WHT is deducted, and a dated signature from a senior person.
Will a UK landlord accept a reference from a Nigerian company?
Often, if it is on letterhead, signed, sent from the company domain and backed by invoices and matching bank credits.
Why is my payment less than my invoice?
Usually because the client deducted Nigerian withholding tax. Ask for the WHT receipt as evidence.
What if my old client will not reply?
Use your contract, invoices, bank statements, WHT receipts and HMRC SA302s instead.
Sources
- PwC Worldwide Tax Summaries: Nigeria, withholding taxes (reviewed 29 May 2026) · accessed Oct 2026
- GOV.UK: Get your SA302 tax calculation (updated 30 Sep 2026) · accessed Oct 2026
- Nationwide for Intermediaries: self-employment income criteria (2026) · 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.