Testing

Test mode behaves exactly like live: the same validation, retries and error shapes. The data is fake but deterministic, every response carries "mode": "test", and nothing is charged.

Two kinds of test credential

What	Sandbox credential	Your own test credentials
How to get it	Printed in the Quickstart	Sign in and request them
Who uses it	Everyone	Only your team
Can change	Yes, we may rotate it	Only when you rotate your secret
Data	Fake, deterministic	Fake, deterministic
Charged	Never	Never

Magic postcodes

In test mode, these postcodes trigger each outcome. Other valid postcodes in England and Wales return fake, deterministic answers.

Postcode	Status	Result
`ZZ1 1AA`	`201` or `200`	A valuation (`201`) or a street analysis (`200`)
`ZZ1 2AA`	`403`	`insufficient-credits`
`ZZ1 3AA`	`403`	`account-blocked`
`ZZ1 4AA`	`422`	`outside-coverage`
`ZZ1 5AA`	`422`	`floor-area-required`
`ZZ1 6AA`	`503`	`data-unavailable`
`ZZ1 7AA`	`504`	`timeout`

For example, to check how your code handles a property outside coverage:

curl -X POST https://api.checkmystreet.co.uk/partners/v1/valuations \
  -H "Authorization: Bearer $TOKEN" \
  -H "Idempotency-Key: 9d41e7a2-6c3b-4f18-8e5a-0b7c2d9f4a61" \
  -H "Content-Type: application/json" \
  -d '{ "postcode": "ZZ1 4AA", "propertyType": "flat", "bedrooms": 2 }'

The response is a 422 problem document with the type outside-coverage.

Keep test figures away from customers

Test figures are fake. Check mode before you show or store a result:

if (valuation.mode === "test") {
  // Fake, deterministic figures: never show these to a customer
}

Before you go live

Handle every outcome in the magic postcode table.
Send an Idempotency-Key with every POST.
Retry 503 and 504 with the same key, and honour Retry-After on 429, but stop on a daily_limit.
Cache tokens for their 30 minute lifetime.
Never show a result carrying "mode": "test" to a customer.

Live credentials follow approval and a first top-up by card. Get access explains the steps.