---
title: "Update a contact property"
method: PATCH
path: "/v1/contact-properties/{property_id}"
tags: ["email-contacts"]
---

# Update a contact property

`PATCH /v1/contact-properties/{property_id}`

## Request

- Base URL: `https://us1.platform.bird.com`
- URL: `https://us1.platform.bird.com/v1/contact-properties/{property_id}`
- Auth: one of:
  - HTTP bearer
  - API key in cookie `bird_session`

Updates a contact property's fallback value, the only mutable field. The key and type cannot be changed after creation; create a new property instead.

## Path parameters

- `property_id` string, required

## Headers

- `Idempotency-Key` string
- `X-Workspace-Id` string
- `X-Organization-Id` string

## Request body

- ContactPropertyUpdateRequest
  - `fallback_value` unknown

## Response `200`

The updated contact property.

- ContactProperty
  - `id` string, required
  - `key` string, required: The property key, used as the key in contact data and as the attribute in the `bird.contact.<key>` broadcast template variable. Lowercase letters, digits, and underscores, starting with a letter. Cannot be changed after creation.
  - `type` 'string' | 'number' | 'boolean' | 'datetime', required: The value type every contact must use for a property. Cannot be changed after creation. `datetime` values are RFC 3339 timestamps with an explicit offset. Examples include `2024-01-15T09:30:00Z` and `2024-01-15T11:30:00+02:00`. A bare date or a time with no offset is rejected. The value is normalized to UTC with second precision on write, so `2024-01-15T11:30:00+02:00` is stored and returned as `2024-01-15T09:30:00Z`, and any fractional seconds are dropped.
  - `fallback_value` unknown
  - `archived` boolean: Whether the property is archived. Archived properties disappear from pickers and cannot be used in new template versions. Published templates keep sending. Stored values remain available to read and update. Unarchive the property to restore it.
  - `created_at` string, date-time, required
  - `updated_at` string, date-time, required

## Other responses

- `400`: Bad request
- `401`: Authentication required
- `403`: Insufficient permissions
- `404`: Resource not found
- `422`: The request has invalid field values, violates a business rule, or carries a query parameter the endpoint does not declare. Field validation errors use `type: validation_error` and include the affected fields in `details`. Business-rule errors identify the failed rule in `type`.
- `429`: Rate limit exceeded
- `500`: Internal server error
- `503`: The service is temporarily unavailable. If `Retry-After` is present, wait for that delay before retrying; otherwise, retry with exponential backoff. Reuse the same idempotency key and request when retrying a mutation.

---

[API](https://skmtc.dev/messagebird/apis/bird-api.md) · [All operations](https://skmtc.dev/messagebird/apis/bird-api/llms.txt) · [OpenAPI document](https://skmtc.dev/messagebird/apis/bird-api/revisions/3e2a50466454?raw)