You can prepopulate parts of the Merchant Signup Form with data from your platform or customer relationship management (CRM) system. Prepopulated forms reduce manual entry, reduce errors, and speed up onboarding to help you guide merchants through a more focused signup experience.
Overview
The Merchant Signup Form is a branded and Payrix Pro-hosted form created during your sandbox onboarding. The Payrix Pro Implementations team provides your signup URL:
https://test-portal.{yourBrand}.com/signup/{yourCode}{yourBrand}: Your branded domain.{yourCode}: The unique path for your form, found on the Signup Forms page in the Payrix Pro portal.
The form submits data to the Payrix Pro API. This means prepopulated values must follow the formats and field rules defined in the API specification. See the Supported Query Parameters section for more details.
Prepopulate Fields with URL Query Parameters
You can add query parameters to your Merchant Signup Form link to prepopulate nonsensitive fields. When merchants open the link, the form loads these values first so that merchants can focus on required fields that need direct input.
Requirements
All prepopulated values must follow these rules:
Queries must not contain SSNs, EINs, TINs, third-party IDs, bank account details, or other PCI-regulated data.
Queries must not contain merchant attestations, agreements, or other consent fields.
Values containing special characters must be URL encoded.
Important!
Sensitive data must be entered by the merchant inside the secure form. Public URLs are not encrypted.
Bracket Notation Syntax
Some Payrix Pro API fields use nested data. The Merchant Signup Form maps these fields using bracket notation. This format shows each value's place inside the nested payload. Each bracket represents one level in the POST /entities API request data.
Nested objects appear in brackets when they are nested within another object. For example, the members object nests within the merchant object:
merchant[members]When an object contains an array of resource payloads, the list items use numeric indexes starting at [0]. The index shows which record you are targeting.
For example, to set the first field for the first and second members inside the merchant.members array, use:
?merchant[members][0][first]=Robert&?merchant[members][1][first]=StevenThis tells the form to place the value inside the merchant object, then inside the members list, then inside each member, and finally into both members' first field.
Special Character Encoding
You must URL encode special characters before adding values to the query. This includes characters like spaces (non-breaking spaces), apostrophes, at signs, and ampersands.
For example, to encode the special characters in Bob's Bike Store:
Encode each space as
%20.Encode the apostrophe as
%27.
The final encoded string is:
Bob%27s%20Bike%20StoreSupported Query Parameters
You can prepopulate most fields defined in the API requests that power the form:
POST /entitiesPOST /merchantsPOST /members
See the Payrix Pro API specification in the Worldpay Developer Hub for details about the relevant fields, including each field’s format and valid values.
Common Prepopulation Scenarios
See the following examples for real-world applications of prepopulated forms.
Industry Default Codes
If your platform supports only one industry, you can prepopulate the MCC and NAICS codes with the related description:
https://test-portal.example.com/signup/sandbox?merchant[mcc]=5940&merchant[naics]=459110&merchant[naicsDescription]=Sporting%20Good%20RetailersKnown Merchant Member Contact
If merchants sign up through your custom application dashboard and you already store their ownership details, you can prepopulate them in the form:
https://test-portal.example.com/signup/sandbox?merchant[members][0][first]=Robert&merchant[members][0][middle]=Karl&merchant[members][0][last]=Wheelwright&merchant[members][0][email]=bob%40bobsbikes.com&merchant[members][0][phone]=5555555555&merchant[members][0][ownership]=10000