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🇬🇧 UK Address Format & Postal Classification (Royal Mail)

Standard UK addresses must end with the POST TOWN (in capitals) and POSTCODE. No country line is used for mail within the UK postal area.

✅ UK Inland (1st / 2nd Class)

Royal Mail treats the following as domestic destinations:

  • England, Scotland, Wales, Northern Ireland
  • Isle of Man
  • Isles of Scilly and all Scottish islands
  • BFPO addresses using valid BF1 postcodes

All share the same inland 1st / 2nd Class rates. The Isle of Man may optionally include “Isle of Man” on the last line.

⚠️ Not Inland (International Rates)

These require International Standard or International Economy postage:

  • Channel Islands – Jersey (JE), Guernsey (GY)
  • Gibraltar – GX11 1AA
  • British Overseas Territories – e.g. Falklands (FIQQ 1ZZ), St Helena (STHL 1ZZ), Turks & Caicos (TKCA 1ZZ), Ascension (ASCN 1ZZ), etc.

Some use “UK-style” postcodes ending in 1ZZ, but they are not part of the UK postal area.

🏷️ Country Lines

  • Do not include England, Scotland, Wales, or Cymru on UK mail — this can cause mis-routing.
  • Short codes (WLS, CYM, IOM) are not valid in postal addresses.
  • Isle of Man may include “Isle of Man” optionally.

🎖️ BFPO Addresses

The British Forces Post Office (BFPO) handles military and MOD mail. Traditionally, these use numeric identifiers such as BFPO 123, which are not valid UK postcodes and can represent locations inside or outside the UK.

To remove ambiguity and ensure consistent treatment:

Only BFPO addresses using valid BF1 postcodes (e.g. BF1 2AB) are considered valid UK addresses.

  • BF1 postcodes are non-geographic but officially recognised by Royal Mail.
  • They allow BFPO destinations to be processed by automated UK postal systems.
  • Plain BFPO ### addresses (without a BF1 postcode) should not be accepted as valid UK postcodes, as they may correspond to overseas bases.

Example of a valid BFPO address:

12345678 Cpl J Smith
BFPO 123
BF1 2AB

📮 Special Case — GIR 0AA

  • GIR 0AA is a unique, non-geographic postcode created for the former Girobank in Bootle, Merseyside.
  • “GIR” stands for Giro (from Italian circulation).
  • It remains valid in Royal Mail’s database for legacy compatibility but has no current geographic use.

✉️ Summary

Use only the town and postcode for all UK destinations. Mail to the Channel Islands, Gibraltar, or any British Overseas Territory requires international postage, even if the address looks like a UK one. BFPO addresses are accepted only when using a valid BF1 postcode.

📬 PaperRun Mailer Policy

While Royal Mail classifies certain destinations as requiring international postage, PaperRun allows mailers to be sent to the following destinations:

✅ Allowed for Mailer Delivery:

  • England, Scotland, Wales, Northern Ireland
  • Isle of Man (IM postcodes)
  • Channel Islands – Jersey (JE), Guernsey (GY)
  • ⚠️ Note: Despite requiring international postage from Royal Mail, we accept these addresses for our mailer service

❌ Not Allowed for Mailer Delivery:

  • Gibraltar (GX11 1AA)
  • British Overseas Territories (FIQQ 1ZZ, STHL 1ZZ, TKCA 1ZZ, ASCN 1ZZ, TDCU 1ZZ, SIQQ 1ZZ, BBND 1ZZ)

This policy is implemented in app/core/utils/addresses/uk_postcodes.py:is_uk_inland_postcode().