UK Postcode Validator
Check British postcodes for USA shippers in seconds. Enter like SW1A 1AA, get VALID/INVALID format check instantly offline with no signup plus outward-inward anatomy and PAF-scope honesty for shippers QA teams applicants travelers and support desks across UK-address workflows daily plus edge-format coverage with deliverability honesty for shippers QA applicants travelers support and hiring across UK-address workflows daily.
Check the official format of a UK postcode and split it into outward and inward parts with this free UK postcode validator.
Calculator Inputs
About UK Postcode
Check British postcodes for USA shippers in seconds. Enter like SW1A 1AA, get VALID/INVALID format check instantly offline with no signup plus outward-inward anatomy and PAF-scope honesty for shippers QA teams applicants travelers and support desks across UK-address workflows daily plus edge-format coverage with deliverability honesty for shippers QA applicants travelers support and hiring across UK-address workflows daily.
Covers AA9A 9AA, A99 9AA, A9A 9AA incl. London SW/EC/WC. Spaces normalized, case ignored.
Parts: Outward SW1A area, inward 1AA street. Space before last 3.
USA: Use for UK-bound labels. USA ZIP separate tool.
Privacy: Local.
Limits: Format only, not PAF existence.
London orders: Austin stores shipping $300,000 UK-bound parcels validate postcodes before labels print. Seattle support confirming $1M client addresses catch typos pre-shipment on 09/22/2026.
Signup forms: Chicago QA validating $2M registration funnels test SW1A, M1, and EH edge formats. Miami students applying to $200,000 UK degrees enter halls addresses correctly first try.
Travel bookings: Denver travelers booking $9,000 Cotswolds cottages match confirmation postcodes to satnav inputs. New York firms hiring $400,000 London transfers verify relocation paperwork.
Anatomy lesson: Outward codes route areas; inward codes pinpoint streets — space before final three always.
Existence limits: Format-valid never proves deliverable — PAF lookups confirm real addresses separately.
Parcel labels: Austin stores shipping $300,000 UK-bound parcels validate postcodes pre-label. Boston researchers posting $150,000 grant files meet deadline addresses on 09/22/2026.
Form QA: Chicago QA validating $2M registration funnels tests SW1A through EH edge formats. Seattle support confirming $1M client addresses catches typos pre-shipment.
Degree applications: Miami students applying to $200,000 UK degrees enter halls addresses correctly first attempt. New York firms hiring $400,000 London transfers verify relocation paperwork.
Cottage bookings: Denver travelers booking $9,000 Cotswolds stays match confirmations to satnav inputs. Phoenix expats forwarding $50,000 mail bundles keep forwarding addresses valid.
PAF reality: Format-valid never proves deliverable — paid PAF lookups confirm existence separately.
Where it is used
USA stores shipping to London, QA validating UK address forms, students applying to UK unis, travelers booking UK stays, and support confirming customer postcodes Austin stores ship $300,000 London orders, Chicago QA validates $2M signup forms, Miami students apply to $200,000 UK degrees, Denver travelers book $9,000 Cotswolds stays, Seattle support confirms $1M client postcodes, and New York firms hire $400,000 London staff Austin stores ship $300,000 London orders, Chicago QA validates $2M signup forms, Miami students apply to $200,000 UK degrees, Denver travelers book $9,000 Cotswolds stays, Seattle support confirms $1M client postcodes, New York firms hire $400,000 London staff, Boston researchers post $150,000 grant files, and Phoenix expats forward $50,000 mail bundles.
How to use the UK Postcode
- UK Postcode — enter the value (e.g. SW1A 1AA).
- Calculate — press the Calculate button to see the result instantly above.
Formula
upper trim → regex ^[A-Z]{1,2}\d[A-Z\d]?\s*\d[A-Z]{2}$ outward inward.
Examples
Buckingham Palace
Manchester
Bad code
Frequently Asked Questions
- Does it check if postcode exists?
- No — format only. For real lookups use Royal Mail PAF.
- Space required?
- One space before last 3 ideal, but auto-tolerated.
- Lowercase?
- Accepted, uppercased internally.
- BFPO?
- Military BFPO formats may fail — use forces post checker.
- USA ZIP?
- Use US ZIP validator for 5-digit. Different system.
- Private?
- Yes. Browser-local.