How to collect unpaid invoices without damaging the customer relationship

Before asking a customer why they have not paid, make sure there is nothing on your side holding things up.

Check:

• Is the invoice actually past its due date?
• Is the amount correct?
• Does it contain the right company and billing details?
• Was a purchase order number required?
• Was the invoice sent to the right person or accounts payable address?
• Did the customer actually receive it?
• Are the agreed payment terms shown correctly?
• Has the payment already arrived but not been reconciled?

This sounds obvious, but it matters.

If the customer needs a PO number before their finance team can process the invoice, another payment reminder will not solve the problem. If the invoice went to a project manager who left the company two months ago, escalating the tone will not help either.

Fix anything that is wrong first. Then resend the corrected invoice and make it clear what changed.

An unpaid invoice tells you very little by itself.

You need to know why it is unpaid.

Common reasons include:

• The customer forgot.
• The invoice was never received.
• It went to the wrong person.
• A PO or other information is missing.
• The invoice is waiting for internal approval.
• The customer disputes the amount or work.
• The customer is having cash flow problems.
• The customer intends to pay but has not given you a date.
• They said they would pay on a particular date and missed it.
• Nobody is responding.

Each one calls for a different response.

A useful first message is often simpler than people think:

Hi [Customer name], I wanted to check on invoice [Invoice number] for [Amount], which was due on [Due date]. Is there anything holding up payment that I can help with?

That question gives the customer an opportunity to tell you what is really going on.

If you want wording for earlier-stage reminders, see our payment reminder email templates.

There is no perfect chasing schedule for every customer.

A long-term client who normally pays reliably should be handled differently from a customer who is regularly 60 days late. Your contract and payment terms matter too.

But having a default process stops overdue invoices from disappearing into somebody's inbox.

The important part is not the exact day.

It is that every step has a purpose.

Sending "just following up again" every seven days is not much of a collections process. Each contact should either get the invoice paid, uncover the blocker, secure a payment date or move the issue to somebody who can resolve it.

For copy you can use once an invoice is clearly overdue, see our past-due invoice email templates.

This is where invoice collection often gets stuck.

The customer replies, but the reply creates another task.

"We'll pay on Friday"

Do not just reply "Thanks."

Confirm the commitment:

Thanks, [Customer name]. I have noted payment of [Amount] for Friday, [Date]. I will check back if we have not received it after then.

Then record the promised date and follow up if it is missed.

A payment promise is useful only if somebody remembers it.

"We need a PO number"

Find the correct PO, update the invoice if necessary, resend it, and ask the customer to confirm it can now be processed.

Do not keep sending overdue reminders while the invoice is still blocked.

"Send this to accounts payable"

Ask for the correct name or email address if you do not already have it.

Send the invoice to the new contact and keep the original person copied if that makes sense for the relationship.

"We haven't received the invoice"

Resend it immediately.

Include the invoice number, amount, original due date and attachment in the same message so there is nothing else for the customer to find.

Then agree when they expect it to be processed.

"There's a problem with the invoice"

Pause normal chasing.

Find out exactly what is disputed and get it to the person in your business who can resolve it.

Continuing to send generic payment reminders while a genuine dispute is open is more likely to frustrate the customer than get you paid.

"We're short on cash"

Ask what they can realistically pay and when.

Depending on the relationship and amount involved, a payment plan may be better than an endless series of missed promises.

"It's already been paid"

Ask for the payment date and remittance information, then check your bank and accounting records.

Do not assume either side is wrong until you have checked.

Our full collections email sequence goes deeper into how to handle each of these replies.

There is a big difference between:

We'll get this sorted soon.

and:

We'll pay $8,500 on September 18.

Whenever possible, turn a vague answer into a specific commitment.

Ask:

Can you confirm the date we should expect payment?

Then keep that date against the invoice.

If the customer misses it, your next message is straightforward:

Hi [Customer name], we had payment of [Amount] scheduled for [Date], but I cannot see it received yet. Can you confirm the updated payment date?

You are no longer asking whether they plan to pay. You are following up on an agreement they already made.

If a customer genuinely cannot pay the whole invoice at once, repeatedly demanding the full amount may not move things forward.

A payment plan can create a realistic route to getting paid.

Agree in writing:

• The total amount outstanding.
• Each installment amount.
• Each payment date.
• How the payments will be made.
• What happens if a payment is missed.

For example, a $12,000 invoice might be split into three agreed payments if both businesses are comfortable with that arrangement.

Do not make the schedule unnecessarily complicated. The easier it is to understand and track, the better.

For larger debts or situations where you are giving up contractual rights, consider getting appropriate professional advice before agreeing new terms.

Sometimes.

The answer depends on where you are, what your contract says and the circumstances of the invoice. The following is general information, not legal advice.

United States

There is no single national rule you can apply to every B2B invoice.

Late fees and interest can depend on state law and the terms agreed with the customer.

Do not suddenly add a penalty simply because an invoice is overdue. Check your contract and the rules that apply to the transaction first.

United Kingdom

For qualifying business-to-business late payments, UK law allows statutory interest at 8% above the Bank of England base rate. If your contract specifies a different interest rate, the statutory rate may not apply.

Businesses can also claim fixed debt recovery compensation. Current GOV.UK guidance lists £40 for debts up to £999.99, £70 for debts from £1,000 to £9,999.99, and £100 for debts of £10,000 or more.

That does not mean you should automatically add interest to every late invoice. For an otherwise good customer who is a few days late, resolving the payment may matter more than escalating the relationship.

Eventually, some invoices stop being a routine accounts receivable problem.

You may have had no response for weeks. A promised payment may have been missed repeatedly. The customer may refuse to pay without raising a genuine dispute.

At that point, decide whether further internal chasing is worth the time.

Possible next steps include:

• A final written notice.
• Escalating to a senior person at the customer.
• Using a commercial collection agency.
• Getting legal advice.
• Making a court claim where appropriate.

The decision should be commercial, not emotional.

Consider the amount owed, the strength of your documentation, whether the debt is disputed, the cost of recovering it and the value of the customer relationship.

In England and Wales, businesses can make a county court claim for money they are owed, including through an online process in eligible cases. Scotland and Northern Ireland use different processes.

Before taking formal action, make sure your records are in order.

You want the invoice, contract or agreed terms, relevant emails, evidence of the work or service provided, payment promises and a clear history of your attempts to resolve the issue.

The easiest invoice to collect is the one that never becomes a collections problem.

A few habits make a difference.

Agree payment terms before the work starts

Do not wait until an invoice is overdue to discover that you expected Net 30 while the customer expected Net 60.

Ask about the customer's payment process

If they require a PO, supplier onboarding form or particular invoice address, get that sorted before billing.

Make invoices easy to understand

Show the correct customer details, invoice number, amount, due date and payment instructions clearly.

Consider deposits or milestone billing

For some service businesses, collecting part of the fee before starting work reduces the amount exposed to late payment.

Remind customers before invoices become seriously overdue

A friendly reminder near the due date can catch simple problems early.

Keep one record of every interaction

Record who you contacted, what they said, any payment date they promised, the current blocker and what needs to happen next.

This becomes especially important when several people in your business are involved in accounts receivable collections.