Short version: TextNow is not a practical provider for an ATA. It doesn't offer SIP credentials for third-party devices, and in 2026 it ended cellular service outside the United States. The reliable way to use a TextNow number on a home phone is to port the number to a SIP provider such as VoIP.ms and configure the HT812 for that provider.
Why TextNow doesn't fit¶
TextNow is an app-based service. Calls are placed through its own apps, which do use SIP behind the scenes, but TextNow does not provide SIP usernames and passwords for users to put into an ATA or desk phone.
Hobbyist projects have pulled SIP credentials out of the app's API since at least 2015, and their own authors describe the approach as unofficial and hacky. An ATA set up this way:
- isn't supported by TextNow,
- may break whenever TextNow changes its app or servers,
- has no reliable 911 address registration.
That's not a good basis for a home phone line, especially one people may need in an emergency.
2026 changes outside the U.S.¶
TextNow announced that TextNow Wireless cellular coverage ends outside the U.S. after July 30. For users in Canada:
- Calling and texting over Wi-Fi in the app continue.
- Numbers are held for three months at no charge.
- TextNow support can provide port-out information so the number can move to another carrier.
Moving a TextNow number to an ATA-friendly provider¶
- Get port-out information from TextNow. Open a chat with TextNow support from the Help Center and request it.
- Check the number is portable to your new provider. Most providers have a portability check during ordering.
- Start a port-in with the new provider (for example, VoIP.ms's port request process), using the account name, number, and port-out information from TextNow. Keep the TextNow account active until the port completes.
- Configure the HT812 for the new provider while you wait. Use a temporary DID if the provider issues one.
- When the port completes, route the number to the ATA's account and register its 911 address.