What is Postcoder?

Postcoder – Customer Data Verification Made Simple.

Trusted by NHS, Sky, KFC, Rightmove, and over 10,000 organisations globally, Postcoder is the all-in-one API platform from Allies Computing that helps businesses collect accurate, verified customer data from the very first interaction. Rated 4.6 stars on G2 and the winner of multiple industry awards, it's the toolkit that keeps forms fast, data clean, and customer journeys completely friction-free.
Postcoder's address lookup lets customers find their address in seconds — whether they type a postcode, begin entering a street name, or search by geographic coordinates. The service draws on Royal Mail PAF, Multiple Residence data, Ordnance Survey AddressBase, and international address databases spanning 249 countries, delivering consistently high match rates both in the UK and overseas.
Beyond addresses, Postcoder packages a full suite of contact data tools into a single API integration:

- Bank account validation: Confirm sort code and account number combinations in real time, retrieve branch-level details, and establish direct debit eligibility before a payment mandate is submitted.
- Email validation: Go beyond syntax checks to assess domain health, detect disposable addresses, and score deliverability risk, keeping CRM lists and transactional inboxes reliable.
- Mobile number validation: Confirm whether a mobile is live and reachable across more than 200 countries, cutting wasted spend on undeliverable SMS communications.
- OTP verification: Add an SMS-based one-time password layer to sign-up, login, or checkout flows to protect accounts and verify identity at the point of entry.

Rather than managing multiple vendors, businesses get one integration, one dashboard, and one support team. Getting started takes minutes — a free trial is available with no payment details required, and the documentation includes ready-to-use sample code across popular languages.

Pricing

Price Starts At:
£27 per 500 credits
Price Overview:
Start with a free trial, then pay-as-you-go or pay monthly. Credit packs start at £27, and monthly plans start at £45. Volume discounts and charity/public sector pricing available.
Free Trial Offered?:
Yes

Integrations

Offers API?:
Yes, Postcoder provides an API

Screenshots and Video

Address autocomplete

Address autocomplete

Company Facts

Company Name:
Allies Computing
Date Founded:
1987
Company Location:
United Kingdom
Company Website:
postcoder.com
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Product Details

Deployment
SaaS
Training Options
Documentation Hub
Online Training
Support
Standard Support
24 Hour Support
Web-Based Support

Product Details

Target Company Sizes
Individual
1-10
11-50
51-200
201-500
501-1000
1001-5000
5001-10000
10001+
Target Organization Types
Mid Size Business
Small Business
Enterprise
Freelance
Nonprofit
Government
Startup
Supported Languages
English

Postcoder Categories and Features

Address Verification Software

Address Validation
Autocomplete
Automatic Formatting
Data Cleansing
Data Discovery
Data Quality Control
Data Verification
Geographic Maps
Geolocation
Metadata Management
Reporting / Analytics
Search / Filter