How to Follow Up on an Unpaid Invoice (With Templates)
WadMaster Editor
Wed, Aug 12, 2026
7 min read
To follow up on an unpaid invoice, send a short, factual reminder as soon as the due date passes. Include the invoice number, amount, due date and payment link or instructions, then ask the customer to confirm a payment date. If there is no reply, follow a pre-decided schedule instead of rewriting an emotional message each time.
The goal is not to sound aggressive. It is to make the next action obvious, keep a written record and find out whether the delay is an oversight, an approval problem, a dispute or a genuine cash-flow issue.
Check these details before you send a reminder
A reminder works best when the invoice itself is easy to verify and pay. Take two minutes to confirm the basics first:
The invoice went to the correct customer and contact person.
The work, delivery or milestone covered by the invoice has been accepted.
The due date has passed, and the balance is still unpaid after checking your bank or payment records.
The invoice number, amount and payment instructions are correct.
Any purchase-order number or approval detail the customer requires is included.
If something is missing, fix it before chasing payment. A customer cannot process an invoice that is sitting with the wrong person or lacks a required reference.
A practical unpaid-invoice follow-up schedule
There is no universal schedule for every client. The timeline below is a sensible starting point for freelancers and small businesses. Adjust it to the payment terms you agreed, the size of the invoice and the relationship.
Two or three days before the due date: send a courtesy reminder, especially for a first invoice or a large amount.
On the due date: send a short note with the invoice or payment link and ask whether anything is blocking approval.
One to three days overdue: confirm that the customer received the invoice and ask for an expected payment date.
An invoice records what a customer owes; a receipt confirms what they paid. Learn when to use each and how to handle deposits and part payments.
Fri, Aug 28, 2026
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Seven days overdue: use a firmer message. Restate the amount and due date, and request a specific payment date.
Fourteen days overdue: call the customer or accounts contact, then send a written summary of what was agreed.
Thirty days overdue: send a final written notice and decide whether to pause new work, renegotiate a payment plan or seek professional recovery advice.
Do not add a late fee or threaten a consequence that was not part of the agreed terms. If you are considering debt recovery, legal action or stopping work, get advice that fits your contract and Nigerian law.
Unpaid invoice reminder templates
Keep each message brief. Customers should be able to understand the issue and act without searching through an old email thread.
Before the due date
Subject: Invoice [number] is due on [date]
Hi [name], a quick reminder that Invoice [number] for [amount] is due on [date]. I have included the invoice/payment link here for convenience. Please let me know if you need anything else to process it.
Thank you, [your name]
One to three days overdue
Subject: Payment reminder for Invoice [number]
Hi [name], I am following up on Invoice [number] for [amount], which was due on [date]. Could you confirm that you received it and let me know when payment is scheduled? The invoice/payment link is here: [link].
If payment has already been sent, please disregard this reminder and share the payment reference when convenient.
Thank you, [your name]
Seven days overdue
Subject: Invoice [number] is now 7 days overdue
Hi [name], Invoice [number] for [amount] remains unpaid and was due on [date]. Please confirm the payment date by [reasonable response date]. If there is an issue with the invoice or the work, tell me today so we can resolve it.
Payment link/instructions: [link or details]
Regards, [your name]
After a promised payment date is missed
Subject: Follow-up on the agreed payment date for Invoice [number]
Hi [name], I am following up because we agreed that Invoice [number] for [amount] would be paid on [promised date], but I have not received the payment. Please confirm the new payment date today, or let me know immediately if there is a problem we need to discuss.
Regards, [your name]
When the customer disputes the invoice
Subject: Resolving the query on Invoice [number]
Hi [name], thank you for explaining the issue with Invoice [number]. My understanding is that the question concerns [brief description]. I have attached [evidence or revised detail]. Please confirm by [date] whether this resolves the issue and when the undisputed amount will be paid.
Regards, [your name]
Should you follow up by email, WhatsApp or phone?
Use the channel the customer normally responds to, but keep the important details in writing. Email is useful for attaching the invoice and preserving a clear record. WhatsApp can get a quick response, especially when that is how you already communicate with the customer. A phone call helps when messages are being ignored or an approval problem needs a real conversation.
After a phone call, send a short written recap: what the customer said, the payment date they promised and any action you agreed to take. This prevents the next reminder from becoming a debate about what was discussed.
What to track so unpaid invoices do not live in your head
The follow-up process becomes much easier when every invoice has a visible status and next action. Track at least:
Customer name and the person responsible for payment.
Invoice number, amount, issue date and due date.
Status: sent, viewed, partly paid, paid, overdue or disputed.
Date and channel of the last reminder.
Any payment date promised by the customer.
The next follow-up date and action.
A spreadsheet can work if it is updated consistently. If you already use WadMaster, the invoicing workflow keeps sent, paid and overdue invoices visible and gives you a direct reminder action, so you are not reconstructing the situation from memory or scattered chats.
Example: following up on a ₦250,000 invoice
Suppose a designer sends Invoice WM-104 for ₦250,000, due on 5 August. On 3 August, she sends a courtesy reminder with the payment link. On 6 August, after confirming that no payment arrived, she asks the client to confirm receipt and provide a payment date.
The client replies that the invoice is waiting for approval and promises payment on 9 August. She records that promise and schedules the next action. When 9 August passes without payment, her message refers to the missed promise instead of starting the conversation again. If the client reports a genuine approval problem, she asks for the accounts contact and the exact information needed.
This process is calm, specific and documented. It also separates money you have invoiced from money you have actually received, which is essential when planning cash flow.
How to reduce late payments next time
Agree the price, scope, deposit and payment deadline before work starts.
Use a specific due date instead of vague wording such as ‘pay soon’.
Send the invoice promptly to the person who can approve it.
Add simple payment instructions or a secure payment link.
Use deposits or milestone payments for large or unfamiliar projects.
Review overdue invoices at the same time every week.
For repeat late payers, tighten future terms before accepting more work.
Consistent follow-up is easier when invoicing is already a habit. This guide to building better invoice and expense habits can help you make the weekly review routine stick.
Make the next action clear
An unpaid invoice should never be a vague worry. Give it a status, a last-contact date and a next action. Start politely, include the facts, ask for a payment date and become clearer at each step. That approach protects the customer relationship without leaving your cash flow to memory.
Put this guide into practice
See the WadMaster feature related to what you just read.
Managing your business finances is hard enough — you don’t need invoicing to make it harder. If you re a freelancer, small business owner, or entrepreneur in Nigeria, finding the right invoicing software for Nigerian businesses can make a huge difference.
