Hi Nemo66,
Welcome to the Microsoft Q&A Platform! Thank you for reaching out regarding your query on Azure API Service management subscription expiry.
Azure API Management (APIM) does not provide built-in features to manage the lifecycle of subscription keys, such as setting expiration dates or automatically rotating keys. Therefore, there is no default expiration period like 180 days. You can develop workflows to automate these processes using tools such as Azure PowerShell or the Azure SDKs
To manage subscription keys and their expiration programmatically, you can use the Azure REST API.
Please let me know in case of further queries