Acquiring is the first step of the sequence, that enable the users to go through authentication and make a payment.

Different information can be included in the API request but there are some specific objects that are required for a successful authentication process.

The API call requires information about billing address to proceed with the payment.

In our case the workflow of the acquiring consists of the below four steps: Create API Request, Receive API Request Response, iSignthis Transaction page and Result page.

In case that you are doing Sofort or POLi integration you should be following the same procedure with acquiring.


You can find the POSTMAN collection here

1. Create API Request

The API request consists of four steps: Method, URL, Header and Body.

Request Method: POST

The API is accessed from the Request URL. This is a combination of our URL and the addition of the following text at the end of the URL: “/v1/authorization/”

URL For Production Environment:

Fill in the appropriate header information. The API Header information is provided by the iSignthis Merchant Support team.

Field Name Field Value
From API client name
Authorization Bearer API token
Content_type application/json


Field Name Field Value
From Test_APIClient
Authorization Bearer TEXnkvZCtFucXebHYwrYLIGbkhjygvBTbxWELCCnCQJTKsx6bYNh5fOjEE
Content_type application/json

In order to generate the “Transaction API call” the following API Objects are required. Each object has a number of specific attributes in order to be successful.

Below you can view each object name, description and whether is required or not. Also, the glossary column has a link that directs you to detailed information about each object, including examples.

Object name Description Required Glossary
merchant Information of the merchant Yes Merchant object
transaction Information of the transaction Yes Transaction object
client Information of the client Yes Client Object
account Information of the account Yes Account object
cardholder Information of the cardholder No* Cardholder object

NOTE : *Cardholder object is only applicable if you have card numbers entered on your own payment page (Server to Server). You must be PCI certified to do this. iSignthis will need to review and approve the PCI documents in order to allow Server to Server integration.s

In the API body request you need to add the “workflow name” and the“id” in the “merchant” object with the ones provided by merchant support.

Test_Workflow” text should be replaced with the  “workflow name”  provided by iSignthis Merchant support team. 


Test_Merchant” text should be replaced with the “merchant_id” provided by iSignthis Merchant support team.


 The API call consists of required fields to proceed with the payment:

– first_name

– last_name

– email

– mobile

– billing_address_street

– billing_address_street_number

– billing_address_city

– billing_address_postal_code

– billing_address_country


Please take a look at the JSON code with the title “Sample JSON body for Acquiring” provided for reference.

Sample JSON body for Acquiring:

    "workflow": "Test_Workflow",
    "merchant":  { 
           "id": "Test_Merchant"
    "transaction": {
        "id": "Test_ID",
        "amount": "100",
        "currency": "AUD",
        "reference": "Test_Ref"
    "client": {
        "first_name": "Shana",
        "last_name": "Barrows",
        "mobile": "+61434444444",
        "billing_address_street": "Arthur Street",
        "billing_address_secondary": "PO Box 24",
        "billing_address_street_number": "42",
        "billing_address_city": "Ashfield",
        "billing_address_postal_code": "2131",
        "billing_address_subdivision": "NSW",
        "billing_address_country": "AU"
    "account": {
        "identifier": "Test_ID"

NOTE: In the “account” object –  identifier is the customer ID that you assigned to your customer. Each “identifier” must be unique and paired with the customer for future transactions.

2. Receive API Request Response

Once the POST is sent, a message will be received as a response. 

Field Type Description
id/uid “String” Unique response identification code.
secret “String” The transaction secret code that can be used to validate ISX notifications.
mode “String” The transaction mode detected by iSignthis.
original_message Object Information about your transaction request.
state “String”  Information about the state of the transaction.
compound_state “String” The ISX meaningful state of the transaction
redirect_url “String” The redirect URL


Sample JSON Payment Response

"id": "e6988b4a-ed1c-4104-9caf-af6bb8769756",
    "uid": "e6988b4a-ed1c-4104-9caf-af6bb8769756",    
    "secret": "159173ee-6309-4806-b499-d2598a2ed21e",
    "context_uid": "e6988b4a-ed1c-4104-9caf-af6bb8769756",
    "mode": "registration",
    "original_message": {
        "merchant_id": "Test_Merchant",
        "transaction_id": "Test_ID",
        "reference": "Test_Ref"
    "transactions": "[]",
    "state": "PENDING",
    "compound_state": "PENDING.VALIDATED_TRANSACTION",
    "redirect_url": ""

Following the redirect_url, will lead to the transaction page.

NOTEIf the API request response is unsuccessful an error will be shown.

3. iSignthis Transaction Page (How to receive notifications)

When the iSignthis transaction page is opened, the customer will be  prompted to insert additional information, if any is required (depending on the settings that you requested), to proceed with the transaction.

For each unsuccessful try a customer makes, an appropriate event notification will be provided to your web hook.

Please check Notifications and  Transaction events section for more information.

4. Results Page

Depending on which page  you have decided to show, the iSignthis results page or your own page will be displayed to the customer with the according message.

Check Transaction events and Transaction states for more information.

If you have any issues don’t hesitate to contact our Merchant support team. We will be happy to help.