Prefill information in Checkout using URL parameters

Fundraise Up’s URL API enables you to pre-fill information in the Checkout modal or Campaign Page using URL parameters. This approach is useful when you are sending traffic to your website from an email marketing campaign and can dynamically set the value of parameters using merge tags.

The URL API may be used in conjunction with the Donate Link Element to create highly-customizable tracking links.

Available parameters

Parameter Format Example Description
firstName String Dawes The first name of the supporter
lastName String Case The last name of the supporter
email String dawes.case@gmail.com The email address of the supporter
amount Float 150 The donation amount. Fundraise Up does not automatically allow donations with cents (or other additional small currency units), but this can be enabled on request by your Solutions Engineer. Learn more →
modifyAmount String no Disallow the supporter to modify the donation amount set by the URL parameter, amount. To fix the donation amount such that supporters can’t change it, pass the modifyAmount=no parameter along with the amount parameter specifying the desired sum. For example: amount=20&modifyAmount=no.
recurring String once Sets the donation frequency
designationId String EHHJ9R36 Set a designation for the donation using the designation’s ID
modifyDesignation String no Disallow the supporter to modify the designation set by the URL parameter, designationId
tributeHonoree String Mom and Dad Sets the value for the tribute honoree
successUrl String View example Sets the redirect URL when a Thank you screen option in Checkout is set to “Redirect to URL”
URL parameters are case-sensitive. Reference the table above for properly formatted parameter names.

Best practices

For most use cases, we recommend not using parameters that include personally identifiable information (PII). PII is any data that can be used to identify an individual, such as a name, address, phone number, or email address.

If you are using marketing tools from Google, such as Ads or Analytics, you should not use URL API parameters that include PII, as the practice goes against Google’s policies. Learn more →


Below are two examples of URLs that have been appended with URL API parameters to prefill information in the Checkout form.

URL with name and email address

This example includes personally identifiable information such as the supporter’s first and last name, and their email address. Prefilling this information streamlines the checkout process, but may affect compliance with your organization’s privacy policies or the policies of its service providers.


A link to a Checkout modal with PII parameters in the URL.


A link to a Campaign Page with PII parameters in the URL.

URL with no PII

This is the same URL as the example above, but parameters with personally identifiable information have been removed. If you are using analytics or ad products, this is the best approach to implementing the URL API.


In the examples above, the parameter, fundraiseupLivemode=no, has been appended to the URL. This enables you to use test mode to explore the areas of Checkout where the URL API has prefilled information.


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