The address API sandbox lets you test UK postcode lookups against Royal Mail PAF before writing production code, using free sandbox keys and the live demo below. The sandbox queries the same dataset as production — ~31M UK delivery points across ~1.8M postcodes — so what you test is exactly what you ship.
Try the live demo now
Type a UK postcode to see a real PAF-style result — no key required:
How do I get sandbox keys?
Create a free account and generate a sandbox key from the dashboard — no card needed:
- Sign up for a free AutoPostcode account
- Generate a sandbox API key in the dashboard
- Run test lookups against real PAF data
- Swap to a production key when you go live
How do I call the sandbox from code?
The sandbox endpoint mirrors production — only the key differs:
const res = await fetch(
"https://api.autopostcode.com/v1/lookup?postcode=SW1A1AA",
{ headers: { Authorization: "Bearer " + process.env.AUTOPOSTCODE_SANDBOX_KEY } }
);
const { addresses } = await res.json();
console.log(addresses); // PAF results, same shape as productionSandbox vs production keys
| Aspect | Sandbox | Production |
|---|---|---|
| Cost | Free test quota | Per lookup |
| Data | Real PAF | Real PAF |
| Rate limits | Test limits | Plan limits |
Read the deeper testing & sandbox guide, follow the API quickstart, and see plans on the pricing page when you're ready to go live.
A modern, UK-first alternative
AutoPostcode uses the same Royal Mail PAF data as Loqate, Fetchify and Ideal Postcodes, with a free sandbox and an affordable per-lookup price.
Frequently asked questions
Is there a sandbox for the address API?
Yes. AutoPostcode offers a free address API sandbox with test keys and a live demo widget, so you can run UK postcode lookups against Royal Mail PAF before writing any production code.
How do I get sandbox keys to test the address API?
Sign up for a free account and generate a sandbox key from the dashboard. Sandbox keys let you make lookups against real PAF data without a paid plan, subject to a generous test quota.
Can I test address lookups without signing up?
Yes — the live demo widget on this page runs example UK postcode lookups instantly. For programmatic testing with your own code, generate a free sandbox key.
Does the sandbox return real Royal Mail PAF data?
Yes. The sandbox queries the same Royal Mail PAF dataset as production, covering ~31M UK delivery points across ~1.8M postcodes, so what you test is what you ship.
What's the difference between sandbox and production keys?
Sandbox keys are for testing and carry a test quota; production keys are billed per lookup and carry your live rate limits. The endpoints and response shapes are identical.
How do I move from sandbox to production?
Swap the sandbox key for a production key — no code changes needed, because the request and response formats match exactly.
Ready to get started?
Add Royal Mail PAF-verified UK address lookup to your site in minutes — start free, no card required.