WordPress.
UK address autocomplete on your existing forms. Install, paste a key, done.
One plugin covers WooCommerce checkout and every major form builder. Where a builder has a native address field we find it and wire it up with no configuration. Where it doesn't — and several of the biggest don't — you add one CSS class per field and it behaves identically. The plugin is free; you pay only for the API calls your forms make.
Three steps, then it's running.
In your dashboard go to Plugins → Add New and search for Postio, then activate. A notice points you at the settings screen so you are never left guessing what to do next.
Settings → Postio. Save the key and test the connection. Signup is free, takes under a minute, and needs no card.
The settings screen lists every builder on your site and says plainly whether it wired itself or needs a class per field — with the snippet printed right there.
Pick your form builder.
Each guide covers that builder specifically — where the setting lives, what to tag, and what to expect.
UK address lookup on the block and classic checkout, plus My Account addresses. No configuration.
Every Address field on every form, wired automatically.
Native Address field, free core, wired automatically.
Native Address field with sub-inputs, free, wired automatically.
Automatic on WPForms Pro. On WPForms Lite, two minutes with CSS classes.
CF7 has no address field, so you tag yours. Two minutes, once per form.
No address field in Ninja Forms, so you tag yours. Two minutes, once per form.
Elementor Pro only. Tag your fields with CSS classes and you are done.
The classes, in full.
For builders with no address field of their own. Only postio-line-1 is required — tag the fields you have and leave out the rest.
| CLASS | FIELD | NOTES |
|---|---|---|
| postio-line-1 | Address line 1 | Required. Doubles as the search box unless you add postio-search. |
| postio-line-2 | Address line 2 | Optional. |
| postio-town | Town or city | Optional. |
| postio-postcode | Postcode | Optional. |
| postio-search | Separate lookup box | Optional. Add this if you want a dedicated "start typing" field above the address. |
What you can change.
Turn any detector off if you would rather it left a particular builder alone. The screen shows which builders it actually found on your site.
Point the finder at any form we do not detect — give it a form selector and a selector per output field. This is the escape hatch for page builders and bespoke themes.
A Postio Address Finder block with its own output mapping in the editor sidebar, for when you want a lookup somewhere that is not a form plugin at all.
Pin the address-finder script to an exact version instead of tracking the latest v1. Useful if you want to control when the widget updates.
Point the plugin at a different Postio environment. Most sites never touch this.
Ready in under a minute.
Sign up, grab a key, paste it in. Your first hundred lookups are on us.