How to Charge Late Payment Fees on Overdue Invoices in the UK

Late payment is one of those small business headaches that never really goes away. You’ve delivered the work, sent the invoice, and paid your own costs - but the customer’s payment date comes and goes.

At that point, it’s normal to wonder: can you charge late payment fees in the UK, and if so, how do you do it without turning a commercial issue into a legal dispute (or losing the customer relationship entirely)?

The good news is that UK law gives businesses real tools for dealing with late payment of invoices - but you need to use them carefully. Some charges are enforceable, others can backfire if they look like penalties or weren’t agreed upfront.

Below, we’ll walk through practical options (including statutory interest, fixed compensation, and contract-based late payment charges), how to build them into your invoicing process, and what to do if the invoice is still unpaid.

What Is A Late Payment Fee (And Is It The Same As Late Payment Interest)?

In everyday business language, a late payment fee is usually a charge you add when an invoice isn’t paid by the due date.

Legally, though, it helps to split this into a few different concepts:

• Late payment interest: interest charged on the outstanding amount because payment is late (e.g. “8% above base rate”).
• Fixed late payment compensation: a set amount you can claim on top of the debt to cover admin and recovery costs (e.g. £40/£70/£100).
• Contractual late payment fees: charges written into your contract or terms (e.g. “£25 admin fee after 14 days overdue”).
• Debt recovery costs: in some cases, you may be able to claim “reasonable recovery costs” in addition to fixed compensation (especially where the fixed amount doesn’t cover the real cost of chasing the debt).

They can all be part of a “late payment” strategy - but they don’t all apply in every scenario.

A Quick Note On Consumer Vs Business Customers

Most of the well-known statutory late payment tools apply to commercial debts (typically business-to-business and business-to-public-authority invoices).

If you invoice consumers (B2C), you generally need to be more cautious. A consumer-facing late payment fee that’s not properly disclosed, or is too high, can be challenged as unfair under consumer protection rules.

So before you roll out any “one size fits all” late payment fee policy, it’s worth checking what kind of customers you usually deal with and making sure your terms match your business model.

When Can You Charge A Late Payment Fee Under UK Law?

For many small businesses, the easiest and most reliable legal basis comes from the Late Payment of Commercial Debts (Interest) Act 1998 (and related regulations). This regime is designed to help businesses deal with late payment of invoices.

In broad terms, if your customer is another business or a public authority and the invoice is late, you may be entitled to claim:

• Statutory interest on the overdue amount (commonly 8% above the Bank of England base rate).
• A fixed compensation amount per invoice:
  • £40 for debts up to £999.99
  • £70 for debts from £1,000 to £9,999.99
  • £100 for debts of £10,000 or more
• Reasonable recovery costs (in some situations), if the fixed compensation doesn’t cover what it actually cost you to chase payment.

That combination can function like a “late payment fee” in practice - but it’s important to describe it accurately (for example, “statutory interest and compensation” rather than an arbitrary penalty charge).

Does Your Contract Replace Statutory Rights?

Businesses often include their own late payment terms. That can be a smart move, but it’s worth knowing that the statutory scheme can still be available unless your contract provides a “substantial remedy” for late payment.

In practice, if your contract provides a fair interest rate and a meaningful route to recover costs, it may displace (or reduce reliance on) the statutory interest/compensation - but if it doesn’t, you may still be able to claim under the late payment legislation.

This is one reason it’s worth getting your terms drafted properly - you want them to be enforceable and commercially effective, not accidentally watered down.

Be Careful Of “Penalty” Late Payment Fees

A key legal risk is charging a late payment fee that looks like a penalty - meaning it’s out of proportion to the real cost or loss caused by the late payment and is mainly designed to punish the payer.

Penalty-style fees are more likely to be challenged and may be unenforceable. A better approach is to use:

• statutory interest/compensation (where available), and/or
• a reasonable admin cost plus interest that reflects your real losses and costs.

How To Set Up Your Contracts And Invoices So Late Payment Fees Are Enforceable

If you want to charge late payment fees (or interest) confidently, the best time to set it up is before the invoice becomes overdue.

In practice, that means making sure you have:

• clear written terms agreed with the customer
• clear payment due dates
• invoices that comply with basic legal and best-practice requirements
• a consistent chasing process (so you don’t undermine your position later)

1) Put Late Payment Terms In Writing (Before The Work Starts)

Verbal agreements and vague “we charge fees for late payment” statements are where disputes begin.

Your late payment clause should ideally cover:

• Payment terms (e.g. “within 14 days of invoice date”)
• Interest (statutory interest, or a specified contractual rate)
• Fixed compensation (if you want to rely on statutory compensation, say so)
• Recovery costs (e.g. debt collection fees, legal costs where permitted)
• Right to suspend services (optional, but helpful if you provide ongoing services)

If you sell services online or regularly onboard new clients, this is typically handled through your Terms and Conditions.

2) Make Sure Your Invoice Is “Chaseable”

One of the most common reasons overdue invoices drag on is that the invoice itself was unclear, missing key details, or went to the wrong person.

Getting the basics right makes it easier to be firm later.

As a starting point, check your invoicing process against UK invoice requirements, including:

• the correct legal name and address for both parties
• an invoice number and invoice date
• a clear description of what you supplied (and when)
• the amount due and VAT details (if applicable)
• a clear payment due date (or payment period) so there’s no confusion about when payment is expected

3) Use Clear Wording On The Invoice

Your invoice is not the best place to introduce new terms (it can be too late), but it is a good place to remind the customer of terms already agreed.

For example, you might include wording like:

• “Payment due by .”
• “Late payments may be subject to statutory interest and fixed compensation under the Late Payment of Commercial Debts legislation.”
• “Our payment terms apply as agreed.”

If you’re regularly dealing with late payment of invoices, tightening up the full process - including reminders and escalation - matters just as much as the legal clause. Practical steps like chasing overdue payments in a consistent way can prevent many disputes from escalating.

A Step-By-Step Process For Charging Late Payment Fees (Without Burning The Relationship)

When an invoice becomes overdue, you’ll usually get better results (and protect your legal position) by escalating in stages.

Here’s a practical approach many small businesses use.

Step 1: Check The Basics First

Before you mention a late payment fee, quickly confirm:

• the invoice was sent to the correct email/address
• the due date has actually passed (watch for weekends/bank holidays if your terms reference “business days”)
• there isn’t a genuine dispute about the work, deliverables, or scope
• your late payment clause applies to this customer type (B2B vs B2C)

If there’s a service dispute, jumping straight to fees can inflame things. In that scenario, you may need to resolve the underlying issue first (or at least show you’re engaging with it).

Step 2: Send A Friendly Payment Reminder

Many late payments aren’t malicious - they’re admin delays, approval bottlenecks, or “we missed it” situations.

A short, polite reminder often works best as your first move. Keep it simple and include:

• the invoice number and amount
• the due date
• how they can pay (bank details / link)
• a request for a payment date if they can’t pay immediately

If you want a structured template, having a consistent Payment Reminder Letter format can save time and keep your tone professional.

Step 3: Escalate With Clear Notice Of Interest/Fees

If the first reminder doesn’t work, your next message should be more direct.

This is usually the best time to say (politely but clearly) that:

• the invoice is overdue
• interest and compensation may apply (if you’re relying on statutory rights, say so)
• you need payment by a specific deadline (e.g. within 7 days)

Even if you haven’t “added” the late payment fee to the invoice yet, flagging that you’ll claim it can encourage payment without immediately escalating the dispute.

Step 4: Send A Final Demand (And Mean It)

If the invoice is still unpaid, it’s usually time for a final demand. At this stage, you want to show you’re serious and you’re building a paper trail.

A good final demand will:

• summarise what is owed (principal + interest/compensation, if applicable)
• attach the invoice(s)
• state a final deadline
• explain what you will do next if payment isn’t received

Having a strong Final Demand Letter helps you stay firm without becoming aggressive.

Step 5: Issue A Letter Before Action (If You’re Prepared To Enforce)

A letter before action is a formal warning that you intend to start legal proceedings if the debt isn’t paid.

It’s not something to throw around lightly - but used properly, it can be very effective.

In most cases you’ll want it to include:

• who the parties are
• what the debt relates to
• the amount due (and how it’s calculated)
• the deadline to pay
• what claim you’ll bring if they don’t pay

If you need a structure to work from, a Letter Before Action should be tailored to your situation (especially if there’s any dispute or multiple invoices involved).

And if you’ve already sent a letter before action and got silence back, you’re not alone - it’s common. The next step needs to be strategic and proportionate. Sometimes you negotiate; sometimes you file. Sometimes you pause because there’s a solvency risk. If you’re stuck, it can help to check what to do where there’s no response to a letter before action.

Common Mistakes To Avoid When Charging Late Payment Fees

Most small businesses don’t get into trouble because they tried to enforce payment - they get into trouble because the fee approach was inconsistent, unclear, or too aggressive.

Here are the mistakes we see most often.

Adding A Late Payment Fee Out Of Nowhere

If your contract never mentioned fees or interest, and you suddenly add “£50 late fee” to an overdue invoice, the customer may refuse to pay it (and may use that dispute to delay the whole invoice).

Even if you can still claim statutory interest/compensation in a B2B situation, it’s better to explain the legal basis rather than inventing a fee.

Charging An Unreasonable Admin Fee

Admin fees should reflect real admin time and cost. If your “admin fee” looks like punishment, you’re more likely to face pushback.

A more defensible approach is:

• use statutory fixed compensation where it applies, and
• only claim extra recovery costs where you can justify them (for example, where you’ve had to engage external help).

Not Following Your Own Process

Consistency is important. If you sometimes enforce fees and sometimes waive them (without a clear reason), customers learn they can ignore payment terms.

It can also create internal confusion - especially if you have staff handling invoicing and credit control.

Escalating Too Fast (Or Too Slow)

If you escalate to legal threats on day 1, you can damage a relationship unnecessarily.

If you wait 6 months, you may have cash flow pain and a harder debt recovery path.

A staged approach (reminder → overdue notice → final demand → letter before action) usually lands best.

Key Takeaways

• A “late payment fee” can mean different things in the UK, including statutory interest, fixed compensation, and contract-based charges - so it’s worth being precise about what you’re claiming.
• For many B2B and public authority invoices, you may be able to claim statutory interest (often 8% above base rate) plus a fixed compensation amount (£40/£70/£100) under late payment legislation.
• Late payment fees and interest are far easier to enforce when they’re clearly written into your terms and agreed before the work starts.
• Your invoices should be clear and compliant, with an unambiguous due date (or payment period), so you’re not giving customers easy reasons to delay or dispute payment.
• A staged chasing process (payment reminder → overdue notice → final demand → letter before action) is usually the most effective way to get paid while keeping things professional.
• Avoid “penalty” fees or surprise charges - they’re more likely to be disputed and can undermine your position.

If you’d like help tightening your payment terms, adding an enforceable late payment fee clause, or recovering overdue invoices without the stress, you can reach us at 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.