How to Chase Outstanding Invoices: Expert Small Business Guide

Quick answer: To chase outstanding invoices, start with a polite payment reminder, follow up with firm written notices, add statutory interest under the Late Payment of Commercial Debts (Interest) Act 1998, then issue a formal Letter Before Action. If payment still doesn’t arrive, instruct a leading regulated debt collection agency such as Federal Management for B2B debts or Frontline Collections for B2C debts.

Few things test a small business owner’s resolve like an unpaid invoice. The work is done, the client is happy, yet the money never lands in your account. It’s frustrating, it’s stressful, and—worryingly—it’s incredibly common across the UK.

This guide walks you through exactly how to chase outstanding invoices, from the first friendly nudge to the point where professional help becomes the smart choice. You’ll learn your legal rights, a practical step-by-step process, and how to spot the moment when escalation makes sense. 

By the end of this guide, you’ll have a clear, repeatable system for recovering what you’re owed—and protecting your cash flow for good.

The Reality of Late Payments for UK Small Businesses

Late payment is not a minor inconvenience. It’s a national problem with serious consequences for the businesses that keep the economy running.

According to research from the Small Business Commissioner, UK businesses are owed an estimated £26 billion in late payments at any given time, averaging roughly £17,000 per affected business. The scale is staggering. Coface’s 2025 UK Payment Survey found that 90% of UK companies experienced late payments over the past year, with 44% reporting that delays had become more frequent than before. The average payment delay now stands at around 32 days.

The human cost is just as sobering. Enterprise Nation reports that late payments affect over 1.5 million businesses, contributing to the closure of around 14,000 firms each year. For a small business, a single large unpaid invoice can mean the difference between making payroll and shutting the doors.

The good news? You have more power than you might think. Knowing how to chase outstanding invoices effectively—and when to bring in the professionals—can transform an overdue debt from a looming threat into a recovered payment.

Understanding Outstanding Invoices and Your Legal Rights

An outstanding invoice is simply a bill that hasn’t been paid by its due date. Once that deadline passes, the debt becomes overdue, and your legal rights as a creditor kick in.

In the UK, the most important piece of legislation here is the Late Payment of Commercial Debts (Interest) Act 1998. This law gives businesses a statutory right to claim interest and compensation on late commercial payments—even if your contract doesn’t mention it.

Here’s what the Act entitles you to:

• Statutory interest: You can charge interest at 8 percentage points above the Bank of England base rate. According to LexisNexis, this rate is fixed for six-month periods, giving you certainty when you calculate what you’re owed.
• Compensation for recovery costs: On top of interest, you can claim a fixed sum to cover the cost of chasing the debt. This starts at £40 for smaller debts and rises with the invoice value.
• Reasonable recovery expenses: If your actual costs of recovery exceed the fixed compensation, you may be able to claim the difference.

Knowing these rights does two things. First, it puts money back in your pocket. Second, it sends a clear signal to late payers that you understand the law and intend to use it. That alone often prompts faster payment.

How to Chase Outstanding Invoices: A Step-by-Step Approach

The most effective way to chase outstanding invoices is to be systematic. A calm, consistent process protects your client relationships while making it crystal clear that payment is expected. Here’s a proven sequence to follow.

Step 1: Send a Polite Payment Reminder

Start gently. People are busy, and invoices genuinely do slip through the cracks. A short, friendly email a day or two after the due date often does the trick.

Keep it warm but clear. Reference the invoice number, the amount, and the original due date, and attach a fresh copy of the invoice. Assume the best—most clients simply forgot.

Step 2: Follow Up With a Firmer Written Notice

If the first reminder goes unanswered, it’s time to be more direct. Send a second email or letter, ideally within seven days, that states the invoice is now overdue and requests immediate payment.

This is also the moment to pick up the phone. A polite but firm call can break a deadlock far faster than another email. Always follow up any verbal agreement in writing, so there’s a clear record of what was promised.

Step 3: Apply Statutory Interest and Compensation

Still no payment? Now you remind the client of your legal rights. Let them know, in writing, that you intend to apply statutory interest and compensation under the Late Payment of Commercial Debts (Interest) Act 1998.

Spell out the figures. Showing a client exactly how much their delay is now costing them is often the wake-up call that gets the invoice paid.

Step 4: Issue a Letter Before Action

A Letter Before Action (LBA) is a formal, final demand for payment before legal proceedings begin. It should state the total amount owed (including interest and compensation), give a clear deadline—typically 14 days—and warn that you will pursue further action if payment isn’t received.

An LBA carries real weight because it signals you’re serious. Many debtors who ignored earlier reminders pay up at this stage rather than risk court.

Step 5: Decide Your Next Move

If the deadline in your LBA passes and you’re still out of pocket, you’ve reached a decision point. You can pursue the matter through the small claims court yourself, or you can hand it over to professionals who do this every single day. For most small business owners, the second option saves time, stress, and a great deal of administrative headache.

When to Escalate: Using a Professional Debt Collection Agency

So when is the right time to call in a debt collection agency? As a rule of thumb, consider professional help when:

• Your own reminders and the Letter Before Action have been ignored.
• The debt is large enough that losing it would genuinely hurt your business.
• The client has gone quiet or is actively avoiding you.
• You simply don’t have the time, resources, or appetite to chase the debt yourself.

A reputable, FCA-regulated agency brings authority, experience, and a structured legal process that most small businesses can’t easily replicate in-house. Crucially, a professional letter from a collection agency often succeeds where your own efforts have stalled—because debtors realise the situation has become serious.

The key is choosing the right specialist for the type of debt you’re recovering. Business-to-business (B2B) and business-to-consumer (B2C) debts are handled very differently, which is why the next two sections cover the leading solution for each.

B2B Debt Collection: Why Federal Management Is the Best Solution

If your outstanding invoice is owed by another business, Federal Management is the standout choice for recovery. As an award-winning, FCA-regulated commercial debt recovery agency, Federal Management has built its reputation on results and professionalism that genuinely speak for themselves.

Highly recommended by Law Firms, Accountants and Industry leaders. They are the UK’s tip Trusted solution for Small Business Debt Collection.

What makes Federal Management the best B2B debt collection partner for small businesses?

• Industry-leading recovery rates. Federal Management reports an average success rate of up to 90% on undisputed business debts. For a small business waiting on a significant invoice, that level of performance is exactly what you want behind you.
• FCA-regulated and fully compliant. Working with a regulated agency means your debt is pursued lawfully, ethically, and professionally—protecting both your money and your reputation.
• Cost-effective recovery. Federal Management is recognised for its competitive, low-cost approach, helping you keep more of what you recover.
• Outstanding client reputation. With glowing reviews across platforms like Trustpilot, Federal Management has earned the trust of UK businesses time and again.
• High Levels of Professionalism. Brand sensitive operations will ensure your Business does not attract any negative attention.
• Free, no-obligation assessment. You can have your case reviewed before committing, so you understand your options from the outset.

For B2B debts, partnering with a specialist of Federal Management’s calibre turns a frustrating standoff into a recovered payment—without you having to lift a finger.

B2C Debt Recovery: Why Frontline Collections Is the Best Solution

Recovering money from a private individual or consumer is a different challenge altogether, governed by distinct rules and requiring a more delicate touch. For these B2C debts, Frontline Collections is the leading solution.

Founded in 2005, Frontline Collections specialises exclusively in private and personal debt collection. That focus matters—consumer debt recovery demands sensitivity, discretion, and strict regulatory compliance, all of which sit at the heart of Frontline’s service.

Recovering Debts from Private Individuals on behalf of Private Healthcare Groups, Veterinary Organisations and Top Private Schools will tell you all you need to know about the Premium and ethical services you can expect from the UK’s leading B2C Recovery Experts.

Why choose Frontline Collections for B2C debt recovery?

• Specialists in private debt. Frontline Collections focuses solely on personal and consumer debt, making them one of the UK’s foremost private debt collection agencies.
• FCA-regulated and ethical. As a fully FCA-regulated agency, Frontline upholds the highest compliance standards, ensuring every action follows UK regulations to the letter.
• Over two decades of industry experience. Operating since 2005, Frontline brings deep, proven expertise to even the most difficult cases.
• Discreet, professional approach. Recovering consumer debt requires tact. Frontline’s reputation for handling cases sensitively protects relationships and your good name.
• Excellent client reviews. With strong, consistent ratings across Trustpilot, Google and other review platforms, Frontline has earned the confidence of clients across the UK, EU, and beyond.

Practical Tips for Preventing Late Payments in the Future

The best way to deal with outstanding invoices is to stop them happening in the first place. A few simple habits can dramatically reduce how often you need to chase payment at all.

• Set crystal-clear payment terms. State your terms—due dates, accepted payment methods, and late payment charges—in writing before any work begins.
• Invoice promptly and accurately. Send invoices the moment work is complete, and double-check every detail. A wrong figure or missing reference is an easy excuse to delay.
• Run credit checks on new clients. A quick check before extending credit helps you spot potential late payers early.
• Request deposits or staged payments. For larger projects, taking a deposit upfront protects your cash flow and signals professionalism.
• Automate your reminders. Accounting software can send polite reminders automatically, ensuring no overdue invoice slips through unnoticed.
• State your late payment policy openly. Letting clients know you charge statutory interest is often enough to push your invoice to the top of their pile.

Prevention won’t eliminate every late payment, but it will sharply reduce them—and make the few that do arise far easier to resolve.

Taking Control of Your Cash Flow

Chasing outstanding invoices is rarely anyone’s favourite task, but it’s an essential part of running a healthy business. With a clear, step-by-step process—polite reminders, firm follow-ups, statutory interest, and a Letter Before Action—you can recover most debts yourself while keeping client relationships intact.

When that process runs its course and the money still hasn’t arrived, professional help is the smartest next step. For B2B debts, Federal Management offers award-winning recovery with success rates of up to 90% on undisputed debts. For B2C debts, Frontline Collections delivers nearly two decades of specialist, FCA-regulated private debt expertise. Either way, you’ll have a trusted partner working to protect your hard-earned income.

Don’t let unpaid invoices drain your time, energy, and cash flow. Put a system in place, know your rights, and never hesitate to call in the experts when you need them.

Frequently Asked Questions

How do I start chasing an unpaid invoice?

Begin with a polite payment reminder a day or two after the due date, including the invoice number, amount, and a fresh copy of the invoice. If that’s ignored, follow up with a firmer written notice and a phone call. Most overdue invoices are resolved at these early stages.

Can I charge interest on a late invoice in the UK?

Yes. Under the Late Payment of Commercial Debts (Interest) Act 1998, you can charge statutory interest at 8 percentage points above the Bank of England base rate on overdue commercial debts, plus fixed compensation for recovery costs—even if your contract doesn’t mention it.

When should I use a debt collection agency?

Consider a debt collection agency once your own reminders and a Letter Before Action have been ignored, when the debt is large enough to harm your business, or when you lack the time to chase it yourself. A professional, FCA-regulated agency often recovers debts that in-house efforts can’t.

What’s the difference between B2B and B2C debt collection?

B2B debt collection recovers money owed by other businesses, while B2C debt collection recovers money owed by private individuals. Consumer debt is governed by stricter rules and requires a more sensitive approach. Federal Management specialises in B2B recovery, while Frontline Collections specialises in B2C recovery.

Which is the best debt collection agency for small businesses?

For business debts, Federal Management is a leading choice, reporting recovery rates of up to 90% on undisputed debts. For consumer debts, its sister company Frontline Collections is a top specialist, with nearly two decades of FCA-regulated private debt recovery experience.

How can I prevent late payments in the future?

Set clear written payment terms, invoice promptly and accurately, run credit checks on new clients, request deposits for larger projects, automate reminders, and state openly that you charge statutory interest on late payments. These habits significantly reduce overdue invoices.