Adding or Changing Merchant Numbers for use with Opayo

Dave McNamara
Dave McNamara
  • Updated

In this article we’ll guide you through the process of adding or changing your Merchant Numbers (also known as Merchant Identification Numbers, or MID) for use with Opayo. We’ll explain what a Merchant Number is and why you would need them. You’ll also find links to other helpful resources.

This article is for Opayo users in the UK and Ireland. If you use Worldpay, Authorize.Net or Moneris, read Card Processing and Merchant Banks for more information.

If you use Spektrix Payments, read Introduction to Spektrix Payments.


What is a Merchant Number?

A Merchant Number (also known as a Merchant Identification Number, or MID) is used to identify your Merchant Account.

When a Customer makes a payment, the Merchant Number ensures the funds reach the Merchant Account. As the payment progresses through each processing stage, the Merchant Number is transmitted alongside the payment information. You may like to think of a Merchant Number as the address and postcode on a letter.


Why would I need new Merchant Numbers?

You’ll need new Merchant numbers for the following:

  • Changing your Merchant/Acquiring Bank
  • Adding an additional Payment Channel, such as Continuous Authority


How do I get new or additional Merchant Numbers?

The process may differ depending on whether you’re requesting new or additional Merchant Numbers.


New Merchant Numbers

If you’ve changed your Merchant/Acquiring Bank, your bank will issue Merchant Numbers as part of opening your new Merchant Account. Contact your Merchant Bank if you have any questions.


Additional Merchant Numbers

To request an additional Merchant Number, for example to use Continuous Authority, you can request this from your Merchant Bank.

TIP: When you request your Merchant Number(s), specify you’ll be using them with Opayo as the Payment Service Provider.

If you’re changing your Merchant Number for EPOS, request a Merchant Number for a third party integrated Chip & PIN machine.

Spektrix will supply your Chip & PIN Machines. Any payment devices supplied by your Merchant Bank will not work with Spektrix.


Which Merchant Numbers do I need?

When changing Merchant Banks, request new Merchant Numbers to use with the following payment channels:

  • Ecommerce (also known as Web Payments): Used for online sales
  • MOTO (Mail Order Telephone Order): Used when performing transactions over the phone
  • EPOS: Used for taking in-person payments through Chip & PIN

TIP: Your Merchant Bank may give you one Merchant Number which covers these Payment Channels. This is called an Omnichannel.


Optional Payment Channels

The following two payment channels are optional. You should only request these Merchant Numbers if you’ll be using these payment channels:

  • Continuous Authority: Used in conjunction with stored cards in Spektrix. You can automatically charge a Customer’s stored card, for example to automatically renew a Membership.
  • American Express: Used to take American Express payments.

TIP: You may need more than one Merchant Number for AMEX if you want to accept AMEX cards online, over the phone or in-person.


How do I update or change the Merchant Numbers in Opayo?

Once you have your new Merchant Number(s), you’ll need to complete some forms and send them back to our Support Team. The forms differ whether you’re adding or changing Merchant Numbers, or if your Merchant Bank is Barclaycard.

TIP: Do not close your existing Merchant Account. You should keep your current Merchant Account open for a minimum of 28 days after submitting your request.


Adding a new Merchant Number

To add a new Merchant Number, for example, Continuous Authority, complete the Merchant Number Addition form.

If your Merchant Bank is Barclaycard, go to the Barclaycard section of this article.


Changing Merchant Numbers

To change Merchant Numbers, for example, if you’ve changed Merchant Banks, complete the Merchant Number Change form and Chip & Pin Setup form.

If your Merchant Bank is Barclaycard, go to the Barclaycard section of this article.



If your Merchant Bank is Barclaycard, you’ll need to complete a Barclaycard Merchant Number Change Form.

Once you've completed your forms, contact Support.


How long does the process take?

Once you’ve sent your completed forms back to Support, our team will send this to Opayo on your behalf.

WARNING: Do not send any forms back to Opayo. Forms sent to Opayo will not be actioned. Our Support Team will manage the process for you.

The process is:

  1. Opayo will change the current Merchant Number(s) on your test Opayo account. This is so the details can be added and then submitted to your Merchant Bank for confirmation.
  2. Confirmation from your bank can take up to five working days.
  3. Once confirmation has been received by Opayo, your new Merchant Number(s) will be added to your live Opayo account.
  4. Once testing is complete, your Merchant Number(s) will be activated.

TIP: Opayo may take up to five working days to make any changes. This may take longer depending on when Opayo receives confirmation from your Merchant Bank that the details are correct.

WARNING: Refunds for payments on the old E-commerce and MOTO Merchant Numbers will still work, but it won't be possible to refund Chip and PIN payments taken on the old Merchant Number once the new Merchant Number has been applied.

A member of our Support Team will contact you to complete the process. This involves making a change to the settings in your system. If you’ve requested a new Merchant Number for EPOS, you'll have to update the configuration of your Chip & PIN machines.

Read the following articles depending your PIN Pad:

This article should give you the information you need to add or change Merchant Numbers in Opayo. To learn more about Payments visit the Manage Payments section of the Support Centre.