SlimPay Help Center

SlimPay Checkout FAQs


SlimPay has developed the Checkout and the REST API in order to offer you best-in-class and innovative solutions to support your business growth.

If you are still using the first version of the Checkout (Webapp) or/and the API SCIM, it’s time for you to upgrade and migrate to the new generation.

You can find below some frequently asked questions related to specific features that may be treated differently from WebApp to Checkout. For more information, you can download the Implementation KIT attached at the bottom of this page (both French and English version). 

This article covers:

How to handle recurring payments for clients who have several subscription? 

Reminder: if you offer SEPA direct debit as a method of payment to your customers, know that the subscriber and the signatory can be two different people. Indeed, the signatory corresponds to the payer (or debtor) but he is not necessarily the user of the service.

The signatory can also subscribe to several subscriptions.

With the Checkout, each subscription generates a mandate (in other words, each new mandate signature is associated with the creation of a new mandate.) In order to make the customer journey of the signatory ideal, you can manage different ways for several subscriptions.

For instance, you can:

  1. Check if the client reference is already existing in our system by using the API call search-mandates
  2. Then, you can choose among those different options:

For SEPA Direct Debits, do not forget the UMR with the client reference and the IBAN in order to have the correct bank account associated with the SDD.

How to manage card recovery?

You can handle it easily from your side:

  1. Find the failed SEPA Direct Debit through the call search-payment-issues
  2. If needed, retrieve the number of retry via the call get-replayed-payment by using the payment Id

Then, initiate a card payment via create order call.

How to be sure that the mandate has been signed?

To be sure that the mandate has been signed, you should take into account the status of the order ( “state” parameter) by getting a  get-orders.

You can find below the values of the parameter “state” obtained with a get-orders call:


“state” in error

“state” in success

“state” non-used








 You should not obtain this “state” as it is the initial status when creating an order & when the user has not yet signed the mandate.



You should not obtain this “state” as it’s corresponding to an unused order with "started=false".






How to update bank details for a mandate?

In order to update bank details on a mandate, you have two possibilities:

  1. Generate a create-order by using an action item: amendBankAccount” which allows the user to enter a new IBAN in the SlimPay Checkout. NB: There is no OTP step as the autorisation had already been signed with the mandate.
  2. Without the user intervention, you can retrieve the UMR via get-mandates call and update the mandate via an update-bank-account call.

For French market, SlimPay allows merchants to benefit from automatic update of bank details and mandates, in the context of bank account switching (mobilité bancaire).

What’s new between API calls of the WebApp and of the Checkout?

The functioning is the same (URLs, calls, errors codes…) except for the following examples:

There is two different types of flows: In & Out corresponding to two items: Payin & Payout with a parameter mentioning the transaction type (Card, SDD, SCT)

  • In = Payin item
  • Out = Payout item


Can i use both the WebApp and the Checkout?

Conflicts between the two versions prevent you from using both. If you do not process card transactions, you can migrate slowly and not all of your sites at the same time.

Is it possible to customize the Checkout’s Design?

Yes, it is possible. We can provide you a unique white label mandate solution. Here you can find the items* you can customize:

  • Header logo
  • URL (domain name)
  • Bottom logo

*If you want to apply your branding to the entire signature page, you can integrate our Checkout in an iFrame mode. It's a charged option, if you're interested please contact our customer support at

Is still notification the same with the Checkout?

The notification is linked to the API you’re using.

SCIM API sent notification with an xml format whereas the REST API is at a json format and contains also the main parameters of a SCIM notification.

Below, you can find an example for an order containing a mandate signature and a SDD:


"_links": {

"self": {

"href": ""


"profile": {

"href": ""


"": {

"href": ""


"": {

"href": ""


"": {

"href": ""


"": {

"href": ""


"": {

"href": ""



"id": "322b9b64-6342-11e8-b50c-000000000000",

"reference": "322b9b64-6342-11e8-b50c-000000000000",

"state": "closed.completed",

"locale": "fr",

"started": true,

"dateCreated": "2018-05-29T13:14:20.000+0000",

"dateStarted": "2018-05-29T13:14:20.000+0000",

"dateClosed": "2018-05-29T13:14:51.000+0000",

"paymentScheme": "SEPA.DIRECT_DEBIT.CORE",

"mandateReused": false,

"sendUserApproval": false,

"checkoutActor": "end_user"


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