Build
Prototypes and small sites
£5/mo
- 50 lookups per day
- 1,250 lookups per month
- UK postcode & address lookup
- Simple integration for web forms
- Email support included
- 14 days free trial
Secure checkout via PayPal. Cancel anytime.
What you get
Everything you need for accurate UK address capture, with simple integration and predictable responses.
⌁
Postcode lookup
Expand postcodes into structured address candidates for fast form completion.
✦
Reliable UK address resolution
Resolve precise addresses from a postcode without relying on complex or enterprise datasets.
✓
Real-time validation
Validate and standardise UK addresses at the point of entry.
About findAddress.io
findAddress.io is a fast, reliable UK postcode lookup and address validation API built for developers and businesses that need accurate data without enterprise-level complexity or cost.
Our RESTful JSON API provides postcode lookup, address autocomplete and real-time validation, helping improve form completion rates, reduce address errors and capture clean, structured UK address data at the point of entry.
Designed for modern web applications, findAddress.io integrates easily into checkout flows, registration forms, CRMs and internal systems using JavaScript, PHP, Node.js and other common stacks.
We focus on delivering broad, practical UK address coverage suitable for the vast majority of commercial use cases, while operating at a fraction of the cost typically associated with full PAF-licensed datasets. For applications that require direct access to PAF or full PAF parity, a Royal Mail PAF licence should be obtained separately.
✓
Reduce checkout friction
Autocomplete and validation help customers complete forms faster, increasing conversions and reducing failed deliveries.
⌁
Structured JSON responses
Predictable API responses including postcode expansion, formatted address data and geocoding.
⚙
Scalable pricing
Clear daily limits and monthly credits designed to support small projects through to growing production applications.
Simple, transparent pricing
Four tiers that scale with usage. Sign up with PayPal in just 3 clicks!
Launch
Capacity for live sites
£10/mo
- 1,000 lookups per day
- 22,000 lookups per month
- Complete UK address retrieval
- Geocoding data included
- Ready for live website use
- Email support included
Secure checkout via PayPal. Cancel anytime.
Grow
For growing traffic!
£20/mo
- 3,000 lookups per day
- 75,000 lookups per month
- Fast UK postcode lookup
- Geocoding data included
- Ideal for ecommerce
- Email support included
Secure checkout via PayPal. Cancel anytime.
Scale
High-volume access
£varies/mo
- 7,500 lookups per day
- 180,000 lookups per month
- High-volume postcode lookup
- Geocoding data included
- Designed for demanding applications
- Email support included
Secure checkout via PayPal. Cancel anytime.
Built for developers
Make a request with your API key and authorised referer, get structured JSON back instantly.
curl -X GET \
"https://findaddress.io/API/10/SW1A2AA" \
-H "content-type: application/json" \
-H "referer: findaddress.io" \
-H "x-api-key: YOUR_API_KEY"
{
"result": "Success",
"callsRemaining": 2928,
"creditsRemaining": 74928,
"latitude": "51.503540",
"longitude": "-0.127695",
"expandedAddress": {
"house": "10",
"street": "Downing street",
"locality": "",
"town": "London",
"district": "Greater london",
"county": "London",
"pCode": "SW1A 2AA"
},
"csvAddress": "10,Downing street,,London,Greater london,London,SW1A 2AA",
"statusCode": "200"
}
Authorised sites and API key
Pass
referer and x-api-key headers. Add authorised domains in your account.
Simple URL format
/API/{house}/{postcode}. If you don't have a house number, use NULL.
Calls and credits returned
Track usage with
callsRemaining and creditsRemaining in every response.
Clear results and error codes
Success, Partial match, and HTTP codes like
400, 401, 429, 500.
Works in any stack
REST + JSON makes it easy to use in PHP, JavaScript, Node.js, Python, Laravel and more.
See more examples and responses on the documentation page.
Frequently asked questions
Common questions about our UK postcode lookup, address autocomplete and validation API.
Do you offer a free trial for the postcode lookup API?
Yes, our "Build" plan includes a 14 day free trial so you can test our UK postcode lookup API in production-like conditions. During the trial you can use postcode lookup, address autocomplete and UK address validation to see how it improves form completion and reduces address errors in ecommerce checkout and registration flows.
Do you provide Royal Mail PAF data?
No. findAddress.io is not affiliated with Royal Mail and does not supply or use the Royal Mail Postcode Address File (PAF) in any way. We provide a practical low cost UK address lookup API designed for most commercial use cases. If a contract or compliance requirement requires the level of accuracy from PAF data, a licensed PAF solution provider should be used.
How accurate is your UK address data?
We combine multiple trusted data sources with validation processes to deliver broad UK address coverage suitable for the vast majority of ecommerce and business applications. The API is designed to return clean, structured UK address data at the point of entry, helping reduce failed deliveries and manual address correction.
Is geocoding included with postcode lookup?
Yes. Geocoding is included with valid lookups and returns latitude and longitude alongside the expanded address. This is useful for mapping, distance calculations and logistics workflows where you want postcode lookup plus geocode results from a UK address validation API.
Can I use the API on multiple domains or apps?
Yes. You can use across multiple domains or applications and use the same API key. This is ideal if you run multiple ecommerce sites, apps or environments and need a consistent UK address autocomplete and postcode lookup integration.
How do daily limits and monthly credits work?
Plans include both daily call limits and monthly credits. Daily limits help protect against unexpected traffic spikes, while monthly credits define your overall usage allowance. This model works well for ecommerce checkout traffic patterns where address validation API usage can vary day to day.
How do I get my API key?
After subscribing to a plan, your API key is displayed in your account dashboard. All you need to do is write your own code, or use one of the examples in our documentation to get started.
What happens if I exceed my usage limits?
If you exceed daily or monthly limits, the API will return a 429 response until limits reset. If you regularly hit limits, upgrading to a higher tier is the simplest way to increase UK postcode lookup capacity for high-traffic checkout and onboarding forms.
Can I integrate with PHP, JavaScript or Node.js?
Yes. findAddress.io is a RESTful JSON API, so it integrates easily with PHP, JavaScript (Fetch/AJAX), Node.js and common frameworks. This makes it straightforward to add UK address autocomplete, postcode lookup and address validation to checkout flows, registration forms and CRMs.
Do you offer custom or enterprise plans?
Yes. If you need higher throughput, custom limits, SLA options or support for larger organisations, we can provide a tailored plan. Contact us if you require an enterprise-ready UK address lookup API for ecommerce or high-volume customer onboarding.