This operation is available in the mail and the form service. If you are using the mail service, we recommend to use the system parameter [bmUrl](🔗) to avoid that a white page with a status message is displayed to the recipient.
Note
Transactional recipient lists (recipient lists that can only be used for API calls) cannot be updated using this operation.
**Parameters**
| Name | Mandatory | Default value | Description |
| bmRecipientId | yes/no | – | The ID of the recipient (usually the email address)<br><br>If used in the mail service, this parameter is not mandatory (the recipient ID is resolved automatically from the bmMailId parameter). <br>If used in the form service, the parameter is mandatory. |
| bmNewRecipientId | no | – | If you want to change the **bmRecipientId** of a recipient, use this parameter, since the parameter **bmRecipientId** is not a regular data field, but an identifier.<br><br>**Note: **Changing the ID of a recipient also affects all other recipient lists of the same client. In addition, all historical information is preserved and assigned to the new ID. |
| bmOverwrite | no | false | If you want to change the **bmRecipientId** of a recipient (see previous parameter) and the specified **bmRecipientId** already exists, an error message is returned and the operation is cancelled. If you set the value of **bmOverwrite** to true, the existing value is overwritten and no error message is returned. |
| bmSanitize | no | – | Set the value of this parameter to true to convert potentially dangerous characters in the supplied recipient data into their respective HTML equivalents. |
| ... | no | – | Any parameter that corresponds to a parameter of the recipient list. |
**Return values**
| Value | Description |
| ok | Recipient data successfully updated |
| wrong\_tag | Authorization failed.<br><br>Error codes:<br><ul><li>501=wrong authentication tag</li> |
<li>502=wrong request IP</li> <li>503=wrong request method</li> <li>504=wrong protocol</li> <li>505=wrong recipient list</li> <li>506=wrong action</li> <li>507=action not found</li></ul><br>If a verification of the authentication tag does not solve the problem, contact [customer support](mailto:[email protected]). | | already\_exist | Only with **bmOverwrite=false**: The new recipient ID transmitted using the parameter **bmNewRecipientId** already exists. To avoid this error and overwrite the existing ID, set **bmOverwrite **to true. | | missing\_id | No **bmRecipientId** was transmitted (mandatory) when using the form service. | | not\_found | No entry with the given **bmRecipientId** was found or an attempt was made to change the recipient ID without providing the **bmNewRecipientId**. | | system\_error | A general error occurred. |
**Example 1**
The dataset field **interests **of the recipient is set to yes. Then, the recipient is forwarded to _www.example.com_.
**Example 2**
The value of the dataset field **myclicks **of the recipient of the email is increased by 3. The dataset field **hasclicked** is set to true. Then, the recipient is forwarded to _www.example.com_.
**Example 3**
The value of the dataset field **myclicks **of the recipient with the ID _[email protected]_ is increased by 3. The dataset field **hasclicked **is set to true.
**Example 4**
The ID of the recipient _[email protected]_ is changed to _[email protected]_.