diff --git a/src/api-explorer/v4-0/Attendees.swagger2.json b/src/api-explorer/v4-0/Attendees.swagger2.json
index 38c16ab37..d95a20f35 100644
--- a/src/api-explorer/v4-0/Attendees.swagger2.json
+++ b/src/api-explorer/v4-0/Attendees.swagger2.json
@@ -470,6 +470,11 @@
           "type": "string",
           "description": "The attendee's first name. Maximum length: 50 characters"
         },
+        "formId": {
+          "type": "string",
+          "format": "uuid",
+          "description": "The attendee's form ID. **Note: This ID is unique to the v4 API and not cross-compatible with v3.**"
+        },
         "HasExceptionsPrevYear": {
           "type": "boolean",
           "description": "Determines whether the attendee had exceptions in the previous year, based on yearly total limits for attendees."
diff --git a/src/api-reference/common/attendees/v4.attendees.markdown b/src/api-reference/common/attendees/v4.attendees.markdown
index 45bae1014..40a00c702 100644
--- a/src/api-reference/common/attendees/v4.attendees.markdown
+++ b/src/api-reference/common/attendees/v4.attendees.markdown
@@ -115,6 +115,7 @@ Content-Type: application/json
           "type": "Text",
           "value": "NYC"
       },
+      "formId": "0f9cf1b6-875c-497d-a78e-9e706bd1c175",
       "id": "fed46bff-8131-4d8b-977a-e81bc14268a4",
       "uri": "https://www.us2.apiconcursolutions.com/v4/attendees/fed46bff-8131-4d8b-977a-e81bc14268a4"
     }
@@ -191,6 +192,7 @@ Content-Type: application/json
           "type": "Text",
           "value": "NYC"
       },
+      "formId": "0f9cf1b6-875c-497d-a78e-9e706bd1c175",
       "id": "fed46bff-8131-4d8b-977a-e81bc14268a4",
       "uri": "https://www.us2.apiconcursolutions.com/v4/attendees/fed46bff-8131-4d8b-977a-e81bc14268a4"
     }
@@ -267,6 +269,7 @@ Content-Type: application/json
           "type": "Text",
           "value": "NYC"
       },
+      "formId": "0f9cf1b6-875c-497d-a78e-9e706bd1c175",
       "id": "fed46bff-8131-4d8b-977a-e81bc14268a4",
       "uri": "https://www.us2.apiconcursolutions.com/v4/attendees/fed46bff-8131-4d8b-977a-e81bc14268a4"
     },
@@ -296,6 +299,7 @@ Content-Type: application/json
           "type": "Text",
           "value": "V5E6W"
       },
+      "formId": "0f9cf1b6-875c-497d-a78e-9e706bd1c175",
       "id": "9647f11d-43f8-4469-ba7c-f7a24efae5b0",
       "uri": "https://us2.api.concursolutions.com/v4/attendees/9647f11d-43f8-4469-ba7c-f7a24efae5b0"
     }
@@ -454,6 +458,7 @@ Name|Type|Format|Description
 `custom1 through custom25`|`object` |[`Custom Field`](#custom-field-schema)|A custom field associated with the attendee. This field may or may not have data, depending on how Expense form fields are configured. If this field is not configured for the attendee type in question, the response excludes this field. For `custom1-20`, maximum length: `100 characters`. For `custom21-25`, maximum length: `48 characters`
 `externalId`|`string` |-| **Required** An identifier for the attendee, usually assigned outside of the SAP Concur systems. Maximum length: `48 characters` **NOTE:** For HCP connectors where information returned to the SAP Concur systems represent one record per attendee+address pair, this value should be a unique identifier for that pair, and the unique identifier for the individual should be placed into a custom field.
 `firstName`|`string` |-| **Required** The attendee's first name. Maximum length: `50 characters`
+`formId`|`string` |`uuid`| **Required** The attendee's form ID. **Note:** This ID is unique to the v4 API and not cross-compatible with v3.
 `hasExceptionsPrevYear`|`boolean`|`true / false`| **Required** If `true`, the attendee had exceptions in the previous year, based on yearly total limits for attendees.
 `hasExceptionsYtd`|`boolean`|`true / false`| **Required** If `true`, the attendee has exceptions in the current year, based on yearly total limits for attendees.
 `id`|`string` |`uuid`| **Required** The unique identifier of the attendee. **Note:** This ID is unique to the v4 API and not cross-compatible with v3.