Depending on the integration type you have implemented, the method for launching the Account Access & E-Mandate flow varies.

In order to launch the Open Banking Account Access and E-Mandate signup flow, the merchant needs:

  • An E-Mandate token (the token returned in the Prepare E-Mandate (POST /emandates) request).
  • Some JavaScript and CSS as described below.


To launch the flow In CHECKOUT mode:

  • Call the Prepare E-Mandate endpoint to retrieve an e-mandate token.
  • Apply CSS and JS file references to your payment page.
  • Add a Setup Subscription button, which calls the aisEmandates() function.

Calling the Prepare E-Mandate Endpoint

To generate an E-Mandate token:

  1. Generate a server-to-server call to /emandates.
  2. Ensure that you have referenced your API Key or OAuth token in the request.
  3. The /emandates service is described in Prepare E-Mandate.
  4. Store the token returned in the response.

Adding the CSS and JS File References

On your subscription setup page you will need to add the following:

For Sandbox

<script src=""></script>
<link rel="stylesheet" type="text/css" href="" />

For Production

<script src=""></script>
<link rel="stylesheet" type="text/css" href="" />

Adding The Set Up Subscription Button

At this point you have:

  • Retrieved an e-mandate token (via the Prepare E-Mandate service).
  • Added the JS and CSS references to your payment page.

To enable the SET UP SUBSCRIPTION button you will need to add an onclick event:

<a class="btn-primary" onclick="aisEmandates()">SET UP SUBSCRIPTION</a>

This onclick event triggers the following JavaScript, which launches the subscription signup pop-up:

NuapayOpenBanking.showEmandateAisp( /*[[${token}]]*/, /*[[${uiUrl}]]*/ );


  • The token is the retrieved E-Mandate token.
  • The uiUrl is = (on Production)

Note that you will need to specify the correct URL based on whether you are testing or working in Production:


An example URL could be:


To launch the flow In REDIRECT mode:

  • Call the Prepare E-Mandate endpoint to retrieve an e-mandate token.
  • Construct the required URL to pass to the PSU as a subscription setup link.
  • Use JavaScript, similar to the following:
NuapayOpenBanking.showEmandateAisp( "fe5d1946-2c57-45c9-865b-600016291081-bo43xegjom", "https:\/\/\/tpp-ui\/");