Overview

Affirm delivers the V3 Disputes API, which offers a cleaner API experience with full support for listing disputes via query params and pagination, richer dispute context via structured evidence fields, and a simplified URL structure.

All new integrations should use V3. V1 will remain available for existing partners, but won't receive further enhancements.

Authentication

While V1 had separate APIs for merchants and partners, V3 is a unified API for both merchant and partner API keys.

Base URL

# V1
/api/partner/v1/merchants/{merchant_id}/disputes

# V3
/api/v3/disputes

`GET /{dispute_id}`

Response body: `status` updates

The status field, which appears on the response object, is also accepted as a query parameter when listing disputes. V3 introduces new status enums with clearer descriptors.

V1 to V3 mapping:

V1 Value	V3 Equivalent
`needs_review`	`action_required_merchant`
`under_review`	`no_merchant_action_needed`
`lost`	`closed_customer_favor`
`won`	`closed_merchant_favor`
`partially_won`	`closed_customer_partial_favor`

📘
Note: The five V1 statuses (lost, needs_review, partially_won, under_review, won) aren't returned by V3 and aren't accepted as status filter values. If your V1 integration relied on these values, you must instead map to the 5 new statuses or use a closed-open state logic based on closed_at.

Response body: Renamed fields

V1 Field	V3 Field	Notes
`amount`	`dispute_amount`	Same field, only renamed
`reason`	`dispute_reason`	Same field, only renamed
`opening_note`	`comments[]`	The new field is an array of strings, rather than a single string.
`opening_note_attachments`	`attached_files[]`	The new field is an array of `{file_name, file_url}` objects, rather than a single file ID string.

Response body: Removed fields

V1 Field	Notes
`open`	Use `status` to determine whether a dispute is open or closed.
`closing_reason`	Removed
`closing_note`	Removed

Response body: New fields

V3 Field	Type	Description
`order_id`	string (nullable)	Your internal merchant order ID associated with the dispute.
`transaction_amount`	integer (nullable)	The original transaction amount in the smallest currency denomination (e.g. cents).
`updated`	datetime (nullable)	Timestamp of when the dispute was last updated.
`extra_evidence[]`	array (nullable)	Structured evidence submitted against the dispute.

Each item in extra_evidence[] can contain one of the following structured objects:

Object	Fields
`shipping_info`	`company_name`, `tracking_number`, `delivery_date`
`communication_info`	`contact_type`, `first_contact_date`, `last_contact_date`, `merchant_contact_name`
`return_info`	`type`, `method`, `return_date`, `store_address`, `shipping_information`

Example:

"extra_evidence": [
      {
          "communication_info": {
              "contact_type": "already_contacted",
              "merchant_contact_name": "Test Contact",
              "first_contact_date": "2025-12-30T00:00:00Z",
              "last_contact_date": "2026-01-30T00:00:00Z"
          }
      },
      {
          "shipping_info": {
              "company_name": "usps",
              "tracking_number": "12312312312",
              "delivery_date": "2025-12-30T00:00:00Z"
          }
      },
      {
          "return_info": {
              "type": "all",
              "return_date": "2025-12-30T00:00:00Z",
              "method": "in_store",
              "store_address": "123 Harbrook Lane"
          }
      }
  ]

Response body: `transition_logs` changes

Within the transition_logs object, we simplify the DisputeEvent object significantly by removing the following V1 fields:

Removed V1 Field	Notes
`id`	Event ID no longer returned.
`dispute_id`	Redundant, given request context.
`is_financial`	Removed
`financial_amount`	Removed
`financial_amount_currency`	Removed
`financial_transaction_type`	Removed
`dispute_snapshot`	Removed

📘
Note: The V3 DisputeEvent field contains only type (string) and created (datetime).

Example:

"transition_logs": [
      {
          "type": "created",
          "created": "2026-03-04T02:29:19Z"
      },
      {
          "type": "customer_evidence_added",
          "created": "2026-03-04T02:29:19Z"
      }
  ]

`GET / [List Disputes]`

With the V3 Disputes API, we introduce support for listing disputes via query parameters with pagination. The following parameters are available:

merchant_id: Required for partners.
status
dispute_reason
created_before
created_after
resolved_before
resolved_after
limit
page_number: Set to 1 by default.

`POST /{dispute_id}/close`

No changes to the request body. However, the response body includes the updated DisputeEvent object. (See the Response body: transition_logs changes section for details.)

`POST /{dispute_id}/submit_evidence`

Request body: Renamed or restructured fields

V1 Field	V3 Equivalent	Notes
`evidence_file_token`	`file_ids[]`	Required. The V3 field is an array of file ID strings, rather than a single value.
(absent)	`comment`	Required. You can now add a comment or summary accompanying the evidence submission.

Request body: New `extra_evidence[]` array

Currently for the new array, merchants and partners can only provide shipping_info:

Object	Fields
`shipping_info`	`company_name`, `tracking_number`, `delivery_date`

Webhooks

Along with updates to the API, we've additionally added new fields to purchase_dispute_opened, purchase_dispute_updated, and purchase_dispute_resolved webhooks.

purchase_dispute_opened

Request body: new fields

Field	Type	Notes
currency	string (ISO 4217)
customer_won_amount	integer	Will be null until dispute is closed
dispute_amount	integer
dispute_reason	string-enum
dispute_status	string-enum	Will use same enums as Dispute API V3 responses
response_due_by	string (ISO 8601)	Will be null is merchant action is not required
transaction_amount	integer
transaction_id	string

Example Payload**

{
created: "2026-03-09T16:58:18.377000Z",
currency: "USD",
customer_won_amount: null,
dispute_amount: 11500,
dispute_id: "EKZP6EBDPBANQE7T",
dispute_reason: "cancellation_or_return_not_processed",
dispute_status: "no_merchant_action_needed",
event_id: "239fbad1-2d78-42d3-9f05-697a5a12fdfd",
event_timestamp: "2026-03-09T16:58:19Z",
event_type: "purchase_dispute_opened",
merchant_id: "0XWX3IT8HD2VOH4Q",
order_id: "test",
response_due_by: null,
transaction_amount: 11500,
transaction_id: "5S30-RRG7"
}

purchase_disputed_updated

Field	Type	Notes
currency	string (ISO 4217)
customer_won_amount	integer	Will be null until dispute is closed
dispute_amount	integer
dispute_reason	string-enum
dispute_status	string-enum	Will use same enums as Dispute API V3 responses
response_due_by	string (ISO 8601)
transaction_amount	integer
transaction_id	string

{
created: "2026-03-09T17:41:37.277000Z",
currency: "USD",
customer_won_amount: null,
dispute_amount: 11500,
dispute_id: "EKZP6EBDPBANQE7T",
dispute_reason: "cancellation_or_return_not_processed",
dispute_status: "action_required_merchant",
event_id: "1512005e-807b-404c-8d2b-5cfff33f13e1",
event_timestamp: "2026-03-09T17:41:38Z",
event_type: "purchase_dispute_updated",
merchant_id: "0XWX3IT8HD2VOH4Q",
order_id: "test",
response_due_by: "2026-03-24T17:41:37.257000Z",
 transaction_amount: 11500,
transaction_id: "5S30-RRG7"

}

purchase_disputed_closed

Field	Type	Notes
currency	string (ISO 4217)
customer_won_amount	integer
dispute_amount	integer
dispute_reason	string-enum
dispute_status	string-enum	Will use same enums as Dispute API V3 responses
response_due_by	string (ISO 8601)	Will be null is merchant action is not required
transaction_amount	integer
transaction_id	string

{
created: "2026-03-09T17:54:22.435000Z",
currency: "USD",
customer_won_amount: 11500,
dispute_amount: 11500,
dispute_id: "EKZP6EBDPBANQE7T",
dispute_reason: "cancellation_or_return_not_processed",
dispute_status: "closed_customer_favor",
event_id: "cf35caa0-19f1-48b6-9607-71dfd04c1202",
event_timestamp: "2026-03-09T17:54:22Z",
event_type: "purchase_dispute_resolved",
merchant_id: "0XWX3IT8HD2VOH4Q",
order_id: "test",
response_due_by: null,
transaction_amount: 11500,
transaction_id: "5S30-RRG7"

}