UK address lookup for WordPress.
Customers find their address in a few keystrokes. You get it complete and spelled right.
One free plugin adds UK address lookup to your WooCommerce checkout and to the forms you already use. Most form builders switch on by themselves the moment you add your API key. The rest take a couple of minutes. You only pay for the lookups your customers make.
Right address, first time.
Wrong or half-typed addresses mean returned parcels and customers chasing you. The plugin swaps typing for picking: the customer starts on their address, Postio shows the matches from Royal Mail's Postcode Address File, and one tap fills the whole thing in.
Customers pick their address from Royal Mail's own list instead of typing it, so what reaches you is complete and spelled right.
A few keystrokes instead of filling five boxes by hand. Line 1, line 2, town and postcode all fill in from one pick.
WooCommerce checkout, contact forms, booking forms, sign-up forms. No new form to build.
It only loads on pages with an address form, only once your key is saved, and never touches your country dropdown.
Running in about five minutes.
In your WordPress dashboard go to Plugins → Add New, search for Postio, then press Install and Activate. It's also on WordPress.org.
Sign up to Postio — it's free, takes under a minute and needs no card. Your key, starting pk_, is under API keys in your dashboard.
In WordPress go to Settings → Postio, paste the key and press Save key. Press Test connection and you should see “Connected — key is active.”
The same screen lists your form builders and says, for each, whether it's wired automatically or needs field classes. If it needs classes, it shows you exactly what to add.
Tip: in your Postio dashboard, open the key and add your website under Allowed URLs so it only works on your site.
Type-ahead or postcode lookup. Your choice.
Pick how your forms work with one toggle under Settings → Postio → How customers find their address. It applies to every address form the plugin handles on your site. Type-ahead is the default, so nothing changes until you switch.
Customers type anything — a house number, a street, a postcode — and matching addresses appear as they type.
- Suggestions update with every few letters.
- They pick theirs and the whole address fills in.
- You choose how many suggestions show at once (see below).
Cost: Searching is free. One lookup is charged when the customer picks an address.
Customers type their full postcode, such as BA2 4QT, and every address at that postcode drops down in a list.
- The list shows how many addresses it found, for example "23 addresses at BA2 4QT".
- Up to about 100 addresses, in a list that scrolls.
- Half a postcode gets a gentle "Keep typing your full postcode" hint.
Cost: One lookup per postcode. Picking from the list costs nothing extra.
Which should I choose?
Both fill in the full, correct address from Royal Mail data. The difference is how the customer gets there, and when you are charged.
- Your customers often know their street before they think of their postcode.
- You want to pay as little as possible for people who browse the checkout and leave — typing costs nothing, only picking an address does.
- Your customers expect the classic "enter your postcode, pick your address" step.
- You deliver to big blocks of flats, where seeing every flat at once is quicker than typing a flat number.
What each one costs.
In lookups, taken from your Postio balance. The price of a lookup is on the pricing page.
| WHAT HAPPENS | TYPE-AHEAD | POSTCODE LOOKUP |
|---|---|---|
| Customer types in the box | Free | Free |
| Postcode looked up | — | One lookup |
| Customer picks an address | One lookup | Free |
| Same postcode again on the same page | — | Not charged again |
| Nothing found | Free | Not charged |
Suggestions to show.
How many addresses type-ahead shows at once. The default is 7, and you can pick any number from 1 to 50 — the list scrolls if it is long. It doesn't affect postcode lookup, which always shows every address at the postcode.
Find your form builder.
Where a builder has its own address field, the plugin finds it and switches on with nothing to set up. Where it doesn't, you add a short label (a CSS class) to each address box once, and it works the same from then on. Each guide walks you through your builder.
UK address lookup on the checkout and in My Account. Nothing to set up.
Every Address field on every form, switched on automatically.
Automatic on WPForms Pro. On WPForms Lite, a few minutes with Custom mappings.
The Address field in free Fluent Forms, switched on automatically.
The Address field in free Forminator, switched on automatically.
Contact Form 7 has no address field, so you label yours. A couple of minutes per form.
Ninja Forms has no address field, so you label yours. A couple of minutes per form.
Elementor Pro only. Label your fields with CSS classes and you are done.
Page builders, bespoke themes and hand-made forms work through Custom mappings on the settings screen. Stuck? Email admin@postio.co.uk.
Five labels, one required.
Only for Contact Form 7, Ninja Forms and Elementor Pro. Add postio-line-1 to your first address line — that's the only one you must have. Add the others to the boxes you have and skip the rest. The settings screen prints these for your builder, ready to copy.
| CLASS | FIELD | NOTES |
|---|---|---|
| postio-line-1 | Address line 1 | Required. Also works 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 | A separate search box | Optional. Gives customers a "find your address" box above the address fields. |
Free plugin. Pay per lookup.
No licence, no “pro” version, every builder included.
Top up your Postio balance and each lookup is taken from it. No monthly fee, no minimum spend, no contract. Auto top-up keeps it from running dry.
Every new account gets 100 free lookups, with no card needed, so you can try it on your real checkout first.
Exactly when a lookup is charged depends on type-ahead or postcode lookup. The current price is on the pricing page.
Everything else on the screen.
All under Settings → Postio. Most shops never need any of these.
Every builder the plugin supports has its own tick box under Form builder detection. Untick one and the plugin leaves that builder's forms alone.
For a form the plugin doesn't know about — a page builder, a bespoke theme, a hand-made form. You tell it which box is the search box and which boxes to fill. Your web developer will know what to put here.
A Postio Address Finder block for the block editor, for an address lookup on any page that isn't a form-plugin form.
Two boxes for pointing the plugin somewhere other than the default. Leave them blank unless we've asked you to change them.
Straight answers.
No. The plugin is free. You pay for the lookups your customers make, from a Postio balance you top up. No monthly fee and no minimum spend.
No. It looks up UK addresses only, from Royal Mail's Postcode Address File. Customers can still type a non-UK address by hand.
No. It fills the address lines, town and postcode, and leaves the country exactly as the customer set it.
Only what the customer types into the address box, your API key and your website's address. No names, emails or order details. Nothing is sent until someone uses an address box.
No. The script is small, comes inside the plugin rather than from another website, and only loads on pages that have an address form.
Your key sits in your web pages, like any address finder's does. In your Postio dashboard, open the key and add your website under Allowed URLs, and it will only work on your site.
Almost certainly, through Custom mappings on the settings screen. If you get stuck, email admin@postio.co.uk and a human will help.
Ready in under a minute.
Sign up, grab a key, paste it in. Your first hundred lookups are on us.