Start with the town and postcode you were given
A UK form may ask for a county even when the address you have contains none. Post Office’s addressing guidance says a county can be omitted when the town and postcode are included. The UPU’s UK guide makes the same distinction. Keep those two components before deciding what belongs in an extra regional field.
For ordinary street addresses, identify the building number or name, street, any necessary locality, post town and full postcode. Keep flat or building details when they are part of the supplied address. The placeholders below show where information goes; they cannot be used as a destination.
Address Line 1 = [recipient’s building number and street] Address Line 2 = [flat, building or locality detail if needed] Town / City = [post town from the confirmed address] Postcode = [complete postcode from the same address] Country = United Kingdom County = [follow the form’s instructions if required]
A post town and a county do different jobs
Use the post town supplied with the address in a Town or City control, checking the form’s instructions. Preserve a dependent locality if it is needed to distinguish the address. Do not substitute a county name for the town just because both appear in a place-name search.
If County is optional and your confirmed address has none, leave it blank. If a website requires one, consult its help or support instead of inventing a value. AddressSample groups UK samples under England, Northern Ireland, Scotland and Wales. Those are tool filters; their labels and codes are not a universal answer to a postal County field.
Keep the whole postcode together
The UPU describes the usual postcode as five to seven letters and digits, with a separating space before the final three characters. Its published formats include M2 5BQ and EC1A 1HQ. These illustrate different shapes, not destinations for your order. Do not impose a five-digit US ZIP rule on a UK field.
In a form test, keep the postal value as a string. Check what happens when a user pastes lowercase text or omits the space, following your application’s normalization rules. A correctly shaped postcode still does not confirm the recipient, building or flat.
Treat the form and the printed label as separate checks
A printed postal address uses lines, while a website may store each component separately. A successful submission can still lose a flat number when the application assembles those fields. Inspect the confirmation screen and any generated label, not just the submit button.
When sending from abroad, retain United Kingdom as the destination country and follow the sending postal operator’s label instructions. For an actual shipment, use the recipient’s confirmed address and the carrier’s lookup or support if something is missing.
A repeatable check with the UK tool
Open the UK generator, choose a source region and click Generate. Keep the source street, locality and postcode from that one result together. The locality is a source field; this tool does not certify it as a Royal Mail post town. For postal labels, check the confirmed address separately.
Save a sample, open Saved addresses and filter to United Kingdom before exporting CSV or JSON. Compare the postcode, spaces and place names with the displayed result. Samples use sourced street and house-number records, with fictional names and phone numbers; the tool adds no invented floor or flat and provides no delivery verification.