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
You can charge interest on a late payment from a Nigerian client if your contract says so: we found no Nigerian statute that adds interest to late business invoices automatically, so the agreed clause is what you rely on. State the rate, when it starts and how it is calculated, and choose in advance how disputes are resolved, because enforcing it across the border means a Nigerian court, a registered foreign judgment or arbitration.
Late payment is one of the most common problems for freelancers in Ghana who work for Nigerian businesses. The question is whether you can add interest when an invoice is overdue, and whether that interest will stand up if the client refuses to pay. The short answer is that interest is a matter of contract. This guide explains why, how to write the clause, how to work out the figure and what enforcement looks like from Ghana. It is information, not legal advice; for a large debt, speak to a lawyer qualified in Nigeria.
Why the contract matters more than the law
Some countries have a statute that gives suppliers interest on late business payments even when the contract is silent. In the sources we checked for Nigeria, we did not find an equivalent law setting statutory interest on late business-to-business invoices. That means that, as a practical matter, the interest you can claim is the interest you agreed. If your contract or accepted terms say nothing, adding a percentage to a reminder email is unlikely to bind the client; a court may award interest when it gives judgment, but that is at its discretion and comes after the cost and delay of a claim.
An agreed late-payment clause has two jobs. It gives you a figure you can point to, and it gives the client a reason to pay on time. Many clients pay late because nothing happens when they do.
Writing the clause
Keep it short and specific. A workable clause covers:
- The due date: a fixed number of days after the invoice date, for example 14 or 30 days.
- The rate: a simple percentage per month or per year on the unpaid amount. State it clearly rather than referring to a rate the client cannot easily look up.
- When interest starts: from the day after the due date.
- How it is calculated: simple interest on the outstanding balance, not compounded.
- The currency: the same currency as the invoice.
- Recovery costs: whether reasonable costs of collecting the debt are added.
- Dispute resolution: which country's law governs and whether disputes go to court or to arbitration.
Choose a rate a Nigerian judge or arbitrator would see as reasonable compensation rather than a penalty. A clause that looks punitive invites argument; a modest, clearly stated rate is easier to enforce and easier for a client's finance team to accept. Put the clause on your invoice as well as in the contract, so it is in front of the person who pays. For a full contract structure, see a freelance contract for Nigerian clients.
Working out the interest: example
Example only. Your contract says payment is due 30 days after invoice and late amounts carry simple interest of 2% per month. You invoice ₦2,000,000 on 1 March; it is due on 31 March and paid on 30 May, 60 days late. Interest is ₦2,000,000 × 2% × 2 months = ₦80,000, so you invoice the client separately for ₦80,000. If the client deducts withholding tax from the original fee, the interest is calculated on the gross amount you invoiced, as your contract should say.
| Days late | Months (simple) | Interest at 2% a month on ₦2,000,000 |
|---|---|---|
| 30 | 1 | ₦40,000 |
| 60 | 2 | ₦80,000 |
| 90 | 3 | ₦120,000 |
Enforcing it from Ghana
If a client will not pay the fee or the interest, there are three main routes.
1. Suing in Nigeria
A claim in a Nigerian court, through a Nigerian lawyer, avoids the step of registering a foreign judgment. It is often the most direct route for a debt owed by a company based in Nigeria.
2. Suing in Ghana and registering the judgment in Nigeria
A Ghanaian judgment does not enforce itself in Nigeria. A guide by the Nigerian firm Streamsowers & Kohn (April 2026) explains that foreign judgments are registered under the Reciprocal Enforcement of Judgments Ordinance 1922 and the Foreign Judgments (Reciprocal Enforcement) Act 1990, within 12 months of the judgment unless a superior court extends the time. Registration can be refused on grounds including lack of notice, lack of jurisdiction, fraud, public policy or the judgment not being final or for a sum of money. The guide does not list which countries are treated as reciprocating, so ask a Nigerian lawyer whether a Ghanaian judgment qualifies before relying on this route.
3. Arbitration
Nigeria's Arbitration and Mediation Act 2023 replaced the older Arbitration and Conciliation Act. Mondaq's summary notes that it makes mediated settlements binding and enforceable and sets time limits for steps such as challenging an arbitrator (14 days). An arbitration clause can be a sensible choice for higher-value contracts, though arbitration has its own costs, so it rarely suits small invoices.
Before it reaches that point
- Send a polite reminder on the due date and another a week later.
- Send a formal letter of demand quoting the contract clause, the invoice, the interest to date and a final payment date.
- Pause further work until the account is up to date, if the contract allows.
- Ask for a part-payment plan in writing if the client has a cash problem.
- Take advice before issuing proceedings; compare the cost of recovery with the debt.
Requiring a deposit or milestone payments reduces the amount at risk; see what to do when a Nigerian client is not paying.
Where Pryme fits
With a Pryme Business Account you can raise invoices that show the due date and your late-payment terms (invoicing), and the Finance agent can prepare reminders for you to approve before anything is sent (Finance agent).
Questions people ask
Is it legal to charge interest on late invoices in Nigeria?
Yes, where the contract provides for it. We did not find a Nigerian statute that adds interest to late business invoices automatically, so the agreed clause matters.
What interest rate can I charge a Nigerian client for late payment?
The rate you both agreed in the contract. Keep it modest and clearly stated, so it reads as compensation rather than a penalty.
Can a Ghana court judgment be enforced in Nigeria?
Foreign judgments can be registered in Nigeria under the 1922 Ordinance and the 1990 Act, within 12 months, if the country is treated as reciprocating. Ask a Nigerian lawyer whether Ghana qualifies.
Can I add interest if my contract did not mention it?
Adding it later is unlikely to bind the client. A court may award interest at its discretion when it gives judgment.
Sources
- Global Legal Post (Streamsowers & Kohn): enforcement of judgments in Nigeria (11 Apr 2026) · accessed Oct 2026
- Mondaq: salient provisions of the Arbitration and Mediation Act 2023 · 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.