United Kingdom — Making Tax Digital, NHS PEPPOL and the B2B wait

The UK digitised VAT reporting through Making Tax Digital from 2019, mandated PEPPOL for NHS suppliers from 2018, but has not yet legislated a federal B2B e-invoicing mandate: an HMRC consultation has been running since February 2025.

Regulatory timeline

• 1980s-1990s — TRADACOMS. Historical UK standard maintained by the ANA (Article Number Association, ancestor of GS1 UK) for retail EDI; still used by Tesco, Sainsbury's, ASDA for ORDHDR / INVOIC messages.
• Public Contracts Regulations 2015 (SI 2015/102). Transposition of EU Directive 2014/55/EU on e-invoicing in public procurement.
• 1 April 2018 — NHS PEPPOL mandate. NHS England requires PEPPOL BIS Billing 3.0 receipt for all Trusts on their goods and services purchases.
• 1 April 2019 — Making Tax Digital for VAT (Phase 1). Obligation for taxpayers with turnover > £85,000 to keep digital records and submit the VAT Return via API.
• 1 April 2021 — Digital Links (Phase 2). End of the copy-paste tolerance window: records must be digitally linked end to end (Notice 700/22, paragraph 4.2.1).
• 1 April 2022 — MTD extended to all VAT-registered businesses. Every VAT-registered business, regardless of turnover, must use MTD-compatible software.
• 19 December 2022 — MTD for Income Tax (ITSA) deferral. HMRC pushes back the ITSA mandate originally planned for 2024 to April 2026 for > £50,000 and April 2027 for > £30,000.
• 13 February 2025 — HMRC e-invoicing consultation. Public consultation launched on B2B and B2G invoice digitisation, closing 7 May 2025.

Deep dives — 10 dedicated pages

Ten dedicated pages drill into every dimension of the UK e-invoicing and EDI ecosystem — the reforms and tax framework (Making Tax Digital, no B2B mandate / 2025 consultation, NHS PEPPOL 2014, post-Brexit ViDA divergence), the technical specifications (VAT 20/5/0% and the zero-rated list, EORI/VAT/Companies House identifiers, CDS customs), and the real-world B2B usage that long pre-dates and outlives regulation (TRADACOMS the UK-origin EDI standard, retail EANCOM the largest in Europe, Odette/VDA automotive).

Reforms and tax framework

• Making Tax Digital for VAT — VAT by API since 2019 · HMRC programme since 1 April 2019: digital records + VAT return via MTD-compatible API, with end-to-end digital link. Extended to all VAT-registered businesses April 2022. Digitises the return, not the invoice.
• No B2B mandate — 2025 e-invoicing consultation · No UK B2B e-invoicing mandate. HMRC + Department for Business and Trade public consultation launched February 2025: voluntary or mandatory, decentralised PEPPOL-style model debated. A deliberate divergence from continental CTC.
• NHS PEPPOL mandate — GS1 + PEPPOL since 2014 · NHS eProcurement Strategy (Department of Health, 2014): GS1 (GTIN/GLN) for identification + PEPPOL 4-corner for messaging. Scan4Safety programme, the UK public sector main PEPPOL deployment.
• Post-Brexit ViDA divergence · A third country since Brexit, the UK is not subject to ViDA nor the 2030 Digital Reporting Requirements (DRR). A sovereign trajectory: MTD for the return, no e-invoice mandate, a decentralised PEPPOL lean. UK↔EU asymmetry.

Technical specs

• VAT regimes — 20 / 5 / 0% and the zero list · Standard 20% (since 4 January 2011), reduced 5% (domestic energy), very broad zero-rated 0% list (food, books, children clothing). The zero-rated / exempt distinction is crucial. £90,000 threshold, VAT Act 1994.
• Identifiers — EORI, VAT number (GB), Companies House · EORI (GB + 12 digits) required for post-Brexit customs, XI variant for Northern Ireland; VAT number GB + 9 digits; 8-character Company Registration Number (Companies House). PEPPOL routing via ICD 0088 / 9932.
• Post-Brexit customs — CDS (Customs Declaration Service) · CDS replaces CHIEF (import Sep 2022, export Mar 2023). GB-EU declarations in UCC data elements, EORI, CN8 codes of the UK Global Tariff. Northern Ireland Protocol + Windsor Framework 2023 (green lane / red lane).

Real-world B2B usage

• TRADACOMS — the UK-origin retail EDI standard (1982) · The first mass-market retail EDI standard in Europe, published 1982 by the ANA (now GS1 UK). Predates EDIFACT and EANCOM. Still in legacy use at historical retail suppliers. The founding anchor of UK EDI.
• Retail EDIFACT — Tesco, Sainsbury's, Asda, Morrisons, Aldi, Lidl · Europe largest retail EDI market by volume. ORDERS / DESADV / INVOIC in EANCOM (GS1 EDIFACT subset), GTIN/GLN identifiers. TRADACOMS legacy converted behind the scenes, migration toward GS1 XML.
• Automotive EDI — Jaguar Land Rover, Nissan, Toyota, Mini, Bentley · Just-in-time supply chain (JIT/JIS): Odette + VDA, DELFOR / DELJIT / DESADV, OFTP2 transport over the ENX network. Post-Brexit: CDS customs and TCA rules of origin strain the just-in-time of UK plants.

Technical schema

Several syntaxes coexist by context:

• MTD VAT API: proprietary HMRC JSON, schema documented at developer.service.hmrc.gov.uk/api-documentation. No invoice format is mandated upstream; only the VAT Return totals are transmitted.
• NHS PEPPOL: PEPPOL BIS Billing 3.0 — UBL 2.1 EN 16931 compliant, transmitted via the PEPPOL network with GLN endpoint identifier (scheme 0088).
• TRADACOMS: proprietary UK EDI standard, sub-segment syntax, INVOIC, ORDHDR, ORDERS messages. Still in production at major retailers.

Sample PEPPOL BIS UBL fragment for the NHS:

<?xml version="1.0" encoding="UTF-8"?>
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2"
         xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2"
         xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2">
  <cbc:CustomizationID>urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0</cbc:CustomizationID>
  <cbc:ProfileID>urn:fdc:peppol.eu:2017:poacc:billing:01:1.0</cbc:ProfileID>
  <cbc:ID>NHS-INV-2026-0042</cbc:ID>
  <cbc:IssueDate>2026-05-16</cbc:IssueDate>
  <cbc:InvoiceTypeCode>380</cbc:InvoiceTypeCode>
  <cbc:DocumentCurrencyCode>GBP</cbc:DocumentCurrencyCode>
  <cac:AccountingSupplierParty>
    <cac:Party>
      <cbc:EndpointID schemeID="0088">5790000435975</cbc:EndpointID>
      <cac:PartyName><cbc:Name>Ediverse Supplies Ltd</cbc:Name></cac:PartyName>
      <cac:PartyTaxScheme>
        <cbc:CompanyID>GB123456789</cbc:CompanyID>
        <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
      </cac:PartyTaxScheme>
    </cac:Party>
  </cac:AccountingSupplierParty>
  <cac:AccountingCustomerParty>
    <cac:Party>
      <cbc:EndpointID schemeID="0088">7300010000001</cbc:EndpointID>
      <cac:PartyName><cbc:Name>NHS Trust Demo</cbc:Name></cac:PartyName>
    </cac:Party>
  </cac:AccountingCustomerParty>
  <cac:LegalMonetaryTotal>
    <cbc:PayableAmount currencyID="GBP">1200.00</cbc:PayableAmount>
  </cac:LegalMonetaryTotal>
</Invoice>

Submission flow

For the NHS, the flow follows the four-corner PEPPOL model via an OpenPeppol accredited Access Point. The recipient SMP (Service Metadata Publisher) is discovered in the PEPPOL SML through DNS.

┌────────────────┐    ┌──────────────────┐    ┌────────────────┐
│ UK supplier    │───>│ Peppol AP        │───>│ NHS Trust      │
│ (ERP)          │UBL │ (Tradeshift, GS1,│UBL │ (procurement)  │
│                │BIS │  TIE Kinetix...) │BIS │                │
└────────────────┘    └──────────────────┘    └────────────────┘
                                │
                                ▼
                ┌──────────────────────────────┐
                │ Peppol Service Metadata      │
                │ Locator (SML) → DNS lookup   │
                └──────────────────────────────┘

For MTD for VAT, accredited vendors (Sage, Xero, QuickBooks, FreeAgent, etc.) call the HMRC API in JSON with OAuth 2.0: POST /organisations/vat/{vrn}/returns. The official list of compatible products is published at gov.uk/guidance/find-software-thats-compatible-with-making-tax-digital-for-vat.

Validation

• HMRC Developer Hub: developer.service.hmrc.gov.uk/api-documentation — sandbox MTD VAT, ITSA, PAYE.
• UK Peppol Authority: NHS Digital was the authority until 2023, transitioning to OpenPeppol for new UK participants.
• OpenPeppol — directory: directory.peppol.eu — UK Participant Identifier lookup.
• GS1 UK — GLN registry: gs1uk.org.

Common pitfalls

1. Digital links mandatory since April 2021. Many vendors keep an intermediate Excel export between the ERP and the MTD module: this is an implicit copy-paste, non-compliant since 2021. HMRC can impose penalties up to 15% of the declared VAT.
2. PEPPOL identifier for the NHS. NHS uses GS1 GLN (scheme 0088), not the VAT number (scheme 9931). Hard-coding 9931 for an NHS Trust recipient leads to a PEPPOL discovery error and rejection by the Access Point.
3. TRADACOMS still in production. Migrating all UK retailers to EDIFACT or PEPPOL in one project under-estimates the TRADACOMS installed base, maintained by specialised middleware (TIE Kinetix, GXS, Generix).
4. No format mandated for B2B. A PDF invoice is legal for VAT provided it carries the mandatory UK fields (HMRC Notice 700, §16). MTD does not change this: the return is digitised, not the invoice itself. Many prospects conflate the two.
5. Northern Ireland — mixed VAT protocol. For goods, Northern Ireland remains in the EU single market: a VAT number starts with XI instead of GB. ERPs must handle both prefixes for intra-EU and UK-EU flows.

Cross-links

• PEPPOL — network used by the NHS.
• EN 16931 — underlying semantic norm.
• EDIFACT — used in UK supply chain.
• EU e-invoicing roadmap 2025-2030.
• Official sources: gov.uk/HMRC, england.nhs.uk, gs1uk.org.