Before you instruct a partner on an overdue commercial invoice, the useful question is not “how angry am I?” — it is whether you can prove the debt. Proof of debt is the paper trail that shows who owes what, under which contract, and that the balance is still undisputed. Without it, chasing burns time and a partner cannot start cleanly.
Debt Collection UK (a trading style of PASECOM GROUP LTD) introduces B2B files to independent partner agencies. We are not solicitors, we are not authorised by the Financial Conduct Authority, and we do not collect consumer credit. PASECOM GROUP LTD was incorporated on 7 April 2026. We introduce commercial claims; we do not issue proceedings. Partners collect. Recovery is not guaranteed.
This guide is for undisputed business-to-business balances. For the wider service path see unpaid invoices and how it works. Related hub reading: letter before action for business debts, recover unpaid invoices from a limited company, payment plan vs debt collection, and aged debt over 90 days.
What “proof of debt” means for an unpaid invoice
In everyday credit control, proof of debt means the documents that establish:
- 1. A contract or accepted order for goods or services.
- 2. That you performed or delivered as agreed.
- 3. That you invoiced the correct legal entity for the correct amount and VAT.
- 4. That payment is overdue under the contract or statutory default period.
- 5. That the debtor has not raised a genuine written dispute that you have left unanswered.
Partners introduced through this site work on a fixed percentage / commission of what they recover (often no-collection, no-fee). Marketing on this site describes 15% only when the client is paid. They still need a coherent pack — collection does not invent missing purchase orders or delivery notes.
Core documents to assemble first
Start with the commercial core. Most B2B files need:
- 1. Invoice(s) and a current statement of account showing the unpaid balance.
- 2. Purchase order, signed quotation, framework terms, or email acceptance that shows the debtor ordered the work or goods.
- 3. Delivery note, POD, timesheets, milestone sign-off, or completion certificate — whatever proves performance in your trade.
- 4. Contract or standard terms that were incorporated (including payment period, interest, and dispute clauses).
- 5. Prior reminders and any final demand, with dates sent and addresses used.
- 6. Any written admission of the balance, broken payment plan, or promise to pay.
If you billed a trading name but the Companies House entity is different, fix that before escalation. Confirm the registered name and company number on Companies House so the chase addresses the correct limited company.
Due date, Late Payment Act rights, and interest figures
Confirm when the invoice became overdue under the contract or, if no period was agreed, under the framework summarised on GOV.UK late commercial payments.
On a qualifying commercial contract for goods or services, the Late Payment of Commercial Debts (Interest) Act 1998 can add statutory interest and fixed compensation once payment is late. Put those figures in your letter before action and in the pack you hand a partner. Asserting statutory rights strengthens a proportionate chase; it does not transfer a partner’s commission onto the debtor, and it does not make recovery free.
Keep a short calculation note: principal, VAT, interest period, base-rate assumptions where relevant, and fixed compensation bands. Vague “plus interest” language is weaker than a stated sum.
Documents that strengthen a Practice Direction letter
Company-versus-company files should usually follow Practice Direction – Pre-Action Conduct and Protocols: set out the claim, list key documents, say what you want and by when, and allow a reasonable time to reply — typically 14 days in a straightforward case.
Your proof pack should therefore include a document schedule you are prepared to list in the letter: invoice numbers, PO references, delivery evidence, and correspondence. The Pre-Action Protocol for Debt Claims applies to claims against individuals, including sole traders. Do not send that sole-trader pack to a limited company. Detail: letter before action for business debts.
If the debtor has already raised a genuine written dispute, pause pre-legal collection until you answer it with evidence. Pre-legal chase is for undisputed commercial debt.
Common gaps that delay instruction
Files stall when:
- 1. The invoice names a different company from the PO or delivery address.
- 2. There is no evidence the goods or services were delivered or accepted.
- 3. Credit notes, retentions, or part-payments are not reconciled on the statement.
- 4. Reminder emails went to a generic inbox with no named contact or registered office copy.
- 5. The balance is already in aged columns but the pack was never refreshed — see aged debt.
None of these gaps is fixed by another soft chase. Rebuild the pack, then decide whether to send a Practice Direction letter, accept a short written payment plan, or instruct a partner.
What to upload when you instruct through this site
When you are ready to instruct, upload the unpaid invoice plus contract or purchase order where you have them, and add a short note on reminders already sent. The claim form on this page routes the file for introduction to a partner. Partners usually charge a fixed percentage of recovered funds (often no-collection, no-fee; 15% only when the client is paid), agreed before they start. This guide is free. Recovery is not free and is not guaranteed. More: how it works.
You remain the creditor. Debt Collection UK does not issue court proceedings. If you later decide to issue, GOV.UK explains how to claim money owed — court fees and solicitor costs are separate from a partner’s contingent commission.
A calm checklist before you instruct
- 1. Confirm legal entity, invoice total, and that the balance is still undisputed.
- 2. Assemble invoice, PO/terms, delivery or performance evidence, and reminder trail.
- 3. Calculate Late Payment Act interest and fixed compensation where they apply.
- 4. Send a proportionate Practice Direction letter (or Debt PAP if the debtor is an individual/sole trader).
- 5. If silence continues, instruct a partner on fixed-percentage terms with the same pack — or decide whether to issue a claim yourself.
- 6. Stop escalation if insolvency appears or a real dispute is still open.
Frequently asked questions
What documents prove an unpaid invoice before debt collection? Typically the invoice and statement, purchase order or accepted terms, delivery or performance evidence, prior reminders, and any written admission of the balance. Entity details from Companies House help when the debtor is a limited company.
Do I need a signed contract to instruct a collection agency? A formal signed contract helps, but many B2B files rest on a purchase order, accepted quote, or incorporated standard terms plus delivery evidence. Missing acceptance is a red flag — fix or explain it before escalation.
Should proof of debt include Late Payment Act interest? Where the Act applies, yes: state statutory interest and fixed compensation in your letter and pack. See the Late Payment of Commercial Debts (Interest) Act 1998 and GOV.UK late commercial payments guidance.
Can a partner collect without a letter before action? Proportionate pre-action conduct still matters for company-versus-company claims under the Practice Direction. Skipping a clear letter often wastes time if the file later moves toward court.
What does instructing through Debt Collection UK cost? Partners usually charge a fixed percentage / commission of what they recover (often no-collection, no-fee). Marketing on this site: 15% only when the client is paid, agreed before they start. Recovery is not guaranteed.
Can Debt Collection UK sue the debtor for me? No. We introduce B2B files to independent partner agencies. We are not solicitors and we do not conduct litigation. You remain the creditor if court action is needed.
When your proof of debt pack is ready, upload the invoice and terms rather than hoping another soft reminder will clear cash. This guide is free. Instructing a partner is not: fees are usually a fixed percentage of what they recover (often no-collection, no-fee; 15% only when the client is paid), agreed before they start. Recovery is not guaranteed.