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One-time password (OTP) verification API Protect your customer accounts with OTP SMS verification

Add effortless two-factor authentication to your customer workflows in minutes. Reduce fraud, impersonation and account takeovers with Postcoder.

Simple SMS one-time password (OTP) verification for all your customers

  • Send an OTP

    Your app uses Postcoder to send an OTP to your customer via SMS

  • Capture the OTP

    Your customer enters the OTP into your app

  • Verify your customer

    Your app uses Postcoder to check whether the OTP is valid

Postcoder OTP verification works with UK mobile numbers only

Secure and seamless authentication throughout your customer journey

  • Registration and onboarding

    Prevent fake account creation and increase conversions by signing up and onboarding real customers only.

  • Logging in

    Secure your authentication flows against account takeovers to maintain the security of customer accounts.

  • Confirming payments

    Safeguard high-value transactions and purchases using one-time passwords to minimise payment fraud.

  • Managing accounts

    Verify password resets, personal detail updates and any other account changes to protect customer data.

  • Recovering accounts

    Provide another way to recover accounts when customers lose access to the email address on their account.

  • Verifying mobile numbers

    Confirm customers have access to the phone number they provided to ensure you have a means to contact them.

Customise the SMS message with your own settings

The small details matter to us. You can personalise your OTP messages to meet your branding and security needs.

  • Personalise the message text
  • Choose OTP length (2-10 digits)
  • Specify OTP expiry time (2 - 30 minutes)
  • Set the SMS sender name

SMS is the simplest method for OTP verification

Sending one-time passwords by SMS to your customers provides a simple way to add an extra layer of security. SMS is accessible to all your customers with a mobile phone, and they don't need to install a new application to receive the messages. It's easy, reliable, and everyone understands what it is. And even better, Postcoder OTP verification is super easy to set up. Sign up for a trial today.

An optimised developer experience

Set up OTP verification in minutes with Postcoder's REST API, sample code and developer-friendly documentation.

  • Javascript
  • python
  • PHP
  • C Sharp
	"to": "07500123456",
    "from": "",
    "message": "Hello from [from]. Your security code is [otp]. It will expire in [expiry] minutes. Do not share this code.",
    "otplength": 6,
    "expiry": 5

HTTP response body

    "id": "OTP45-12345-12345-1234X"

Text message content

Hello from Your security code is 532132. It will expire in 5 minutes. Do not share this code.
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Having Postcoder on our checkout page has really helped ... Customers spend much less time adding their details which in turn made for a much more pleasant transaction.

Alex Woods Digital Marketing Executive at Victorian Plumbing

Free support

Postcoder is supported by our own team of experts that specialise in email validation, data quality, usability, privacy and technical integration. When you choose Postcoder, our team is your team and we're here for you if you need us, at no extra cost.

Tracking usage

Understanding how your account is being used is important, so we make it easy for you. You can view usage reports, configure email alerts and check your remaining credit balance.

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Perfect pricing

We have payment options to suit every type of business, from pay-as-you-go credit packs to monthly plans to high volume licences.

What our customers say

Loveholidays - A customer who uses Postcoder

"It took us under a day to swap out our old system with Postcoder and we have been enjoying it ever since."

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"We've been really pleased with the uptime and reliability of the service."

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