Document format and locale facts for United Kingdom

Why these defaults?

The country code comes from ISO 3166. Unicode CLDR supplies presentation-oriented locale, currency, paper, date, language, calendar, numbering, and direction metadata. Defaults reduce setup time; they do not decide what a valid document must contain.

Recorded official or regional-official language tags: en, cy, ga, gd.

Selected national claims reviewed

Document vocabulary and checks

Ordinary UK invoice particulars, conditional VAT-invoice particulars, the general six-year VAT record period and electronic-invoice controls are reviewed from current GOV.UK/HMRC guidance. VAT registration, simplified and special schemes, Northern Ireland transaction context, sectors and transaction-specific treatment remain separate checks.

Evidence snapshot: 4 official sources · last reviewed 2026-07-19. This is scoped guidance, not a jurisdiction-wide compliance certification.

Tax labels: VAT. Business identifier labels: VAT Registration Number / Company Registration Number (CRN).

• Guidance: An ordinary UK invoice includes a unique number; supplier and customer names and addresses; a clear description; supply and invoice dates; amounts charged; VAT when applicable; and the total. Sole traders and limited companies have additional identity rules described by GOV.UK.Evidence GB_GOV_UK · reviewed 2026-07-19 · review by 2027-01-19 · automation advisory only
• Guidance: Only VAT-registered businesses issue VAT invoices. Full VAT invoices add the sequential invoice number, tax point, issue date, supplier name/address/VAT number, customer name/address, sufficient supply description and quantity or extent, and net, VAT and gross values. Applicability, simplified invoices and special schemes must be checked separately.Evidence GB_HMRC_VAT_RECORDS · reviewed 2026-07-19 · review by 2027-01-19 · automation advisory only
• Required when applicable: Include the supplier VAT registration number when a VAT-registered business issues a VAT invoice. Registration and VAT-invoice applicability must be established separately; this guidance does not make the field mandatory for every UK invoice.Evidence GB_HMRC_VAT_RECORDS · reviewed 2026-07-19 · review by 2027-01-19 · automation advisory only
• Guidance: VAT-registered businesses generally keep VAT business records and invoice copies for at least six years; OSS/MOSS and special-scheme rules can require longer or different treatment.Evidence GB_HMRC_VAT_RECORDS, GB_HMRC_RETENTION · reviewed 2026-07-19 · review by 2027-01-19 · automation advisory only
• Guidance: Electronic VAT invoices contain the same information as paper invoices. Issuers remain responsible for authenticity, integrity, legibility, reproducibility and storage; a Formnivo PDF is not proof that those controls or Making Tax Digital records have been satisfied.Evidence GB_HMRC_EINVOICING · reviewed 2026-07-19 · review by 2027-01-19 · automation advisory only

Identifier format guidance: 9 digits, optional 'GB' prefix (e.g. 123456789 or GB123456789)