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28 articles on Technical and UK e-invoicing.

Last updated 20 October 2026

20 Oct 2026Common Peppol validation errors explained (with fixes)The Peppol BIS Billing 3.0 validation errors UK senders hit most, with the exact rule text, why each one fires and how to fix it in the UBL.Guide · 7 min
20 Oct 2026E-invoice credit notes in the UK: how they work in PeppolHow to issue a UK credit note as a Peppol e-invoice: credit note vs negative invoice, type code 381, the original invoice reference and a valid UBL example.Guide · 6 min
20 Oct 2026Does a PDF invoice count as an e-invoice? Not from 2029HMRC accepts emailed PDFs as electronic invoices today, but the 2029 mandate needs structured, machine-readable data. A PDF alone will not be enough.Explainer · 4 min
20 Oct 2026Reverse charge construction e-invoices in Peppol (AE code)How to issue a UK construction domestic reverse charge invoice in Peppol: the AE code, HMRC's wording rules, a valid UBL example and the BR-AE errors to avoid.Guide · 6 min
20 Oct 2026How long to keep e-invoices: HMRC retention and archiving rulesHMRC says keep VAT invoices, including e-invoices, for 6 years. Here's what to store, where you can store it, and how other tax rules can make it longer.Guide · 5 min
20 Oct 2026UK Peppol invoice XML example (UBL, validated)A complete UK Peppol BIS Billing 3.0 invoice in UBL XML, with GBP, 20% and zero-rated lines and a delivery charge, validated against EN 16931 and Peppol rules.Guide · 5 min
20 Oct 2026ERP e-invoicing in the UK: SAP, Oracle, Dynamics, NetSuiteHow to plan UK Peppol e-invoicing on an ERP such as SAP, Oracle, Microsoft Dynamics or NetSuite: integration options, questions for vendors and project risks.Guide · 5 min
20 Oct 2026Law firm disbursements on e-invoices: 2029 guideHow law firms and other professional services firms should handle disbursements, recharges and confidential detail when invoices become e-invoices.Guide · 6 min
20 Oct 2026E-invoicing vs EDI: what UK businesses need to knowEDI is an older, bilateral way to swap structured documents. Peppol e-invoicing is an open network. Here's how they differ and what 2029 may mean for EDI users.Explainer · 5 min
20 Oct 2026EN 16931 explained: the e-invoice standard behind PeppolEN 16931 is the European standard defining what an e-invoice contains. What it is, how BT codes and BR rules work, how Peppol builds on it, and the UK angle.Explainer · 5 min
20 Oct 2026The five-corner model explained: will the UK use it?A five-corner model adds the tax authority as a fifth corner that receives invoice data. The UK starts in 2029 with four corners and no real-time reporting.Explainer · 4 min
20 Oct 2026How to attach a PDF to a Peppol invoice (BG-24)How to attach a PDF, timesheet or spreadsheet to a Peppol e-invoice: allowed file types, the exact UBL, and the rules that reject attachments.Guide · 5 min
20 Oct 2026Foreign currency VAT invoices as e-invoices: showing VAT in GBPYou can invoice in euros or dollars, but HMRC wants total VAT in sterling. How to do that in a Peppol e-invoice with BT-6 and BT-111, and errors to avoid.Guide · 5 min
20 Oct 2026Peppol BIS Billing 3.0: a guide for UK businessesPeppol BIS Billing 3.0 is the invoice and credit note format used on Peppol. What it contains, the rules UK invoices trip on, current versions and UK unknowns.Guide · 5 min
20 Oct 2026How to check if a UK company is on PeppolSearch the free Peppol Directory by company name or Peppol ID. A missing listing does not prove a business is not on Peppol; here is how to check properly.Guide · 5 min
20 Oct 2026Peppol scheme 9932 and 0088: EAS codes for UK businesses9932 is the Peppol scheme code for a UK VAT number and 0088 is a GS1 Global Location Number. How each is used, where it goes in the invoice and what to avoid.Guide · 5 min
20 Oct 2026Peppol ID Isle of Man: which identifier to useThere is no Isle of Man Peppol scheme. Manx VAT-registered businesses use 9932 (UK VAT number) with their 00-prefixed number, e.g. 9932:gb001234567.Guide · 4 min
20 Oct 2026Peppol ID Northern Ireland: GB or XI VAT number?There is no XI scheme in Peppol. Northern Ireland businesses normally register a 9932 ID using their GB VAT number; XI is for EU goods trade documentation.Guide · 5 min
20 Oct 2026Peppol Invoice Response vs MLR and MLS explainedMLR and its successor MLS tell the sender's provider if an invoice was delivered or rejected; Invoice Response tells the supplier what the buyer did with it.Explainer · 5 min
20 Oct 2026Peppol ID UK: how participant identifiers workA UK Peppol ID is a scheme code plus a value, such as 9932:gb123456789 for a VAT number. Here is the exact format, the case rules and which ID to use.Guide · 5 min
20 Oct 2026Peppol SMP and SML explained: how invoices find the buyerThe SML is Peppol's DNS-based locator and the SMP is the registry of what each participant can receive. How a lookup works, step by step, with a UK example.Explainer · 4 min
20 Oct 2026BR-CO-15 error: Invoice total amount with VAT explained and fixedBR-CO-15 fires when BT-112 does not equal BT-109 plus BT-110, or the UBL has more than one VAT total in the invoice currency. Causes, tests and fixes with UBL.Guide · 5 min
20 Oct 2026Public Procurement (Electronic Invoices etc.) Regulations 2019The 2019 regulations made UK public bodies accept EN 16931 e-invoices. What they required, how Scotland differs, what replaced them, and what 2029 adds.Explainer · 6 min
20 Oct 2026Buyer reference (BT-10) and PO number in Peppol invoicesPeppol invoices need a buyer reference (BT-10) or a PO reference (BT-13) or rule PEPPOL-EN16931-R003 rejects them. What each is for and how to fill it.Guide · 5 min
20 Oct 2026Self-billing and e-invoicing: what HMRC rules mean for 2029Self-billing will survive e-invoicing: Peppol has a self-billing standard and HMRC's Notice 700/62 still applies. Here's what is confirmed and what is open.Guide · 4 min
20 Oct 2026UBL vs CII: which e-invoice format should UK businesses use?UBL and CII are the two XML syntaxes for EN 16931 e-invoices. How they differ, which one Peppol requires, and what it means for UK businesses before 2029.Explainer · 4 min
20 Oct 2026UK VAT category codes in Peppol: S, Z, E, AE and O explainedWhich Peppol VAT category code to use for UK standard, reduced, zero-rated, exempt, outside-scope and reverse charge supplies, and the rules each triggers.Guide · 6 min
20 Oct 2026What must a VAT invoice include? HMRC rules mapped to e-invoicesHMRC's list of what a full VAT invoice must show, and where each item goes in a Peppol BIS Billing 3.0 e-invoice, including the fields Peppol adds on top.Guide · 6 min