"This account is registered to another device"

You open the app on a new phone and it stops on a screen headed New Device Detected: "Your account is currently registered to" — then the name of your old phone — "You are now signing in from" this one. Nothing else loads until you answer it.

Atteny ties your account to one phone, so a clock-in can't be handed round the team. The first phone you sign in on is registered silently — this screen only appears when the phone changes.

Most of the time you can fix it yourself

Tap Switch to This Device. The old phone is dropped, this one is registered, and the app carries on. The screen tells you how many switches you have left: you get two per calendar month, and the count resets on the 1st.

The other button, Sign Out, only returns you to login and changes nothing.

If you've already used both switches

You'll see Device Limit Reached and "You've reached the maximum of 2 device changes this month. Please contact your administrator."

That is the real answer: an administrator has to clear it for you, and a manager can't — the setting is deliberately admin-only. Ask an admin to open Employees → your name → Employment → Device Registration and press Remove Device. They'll see "Device removed. Employee can register a new device on next sign-in." Sign in again on the new phone and it registers itself.

Two lookalike messages

• "Clock-in blocked: this device is not registered for your account. Please use your registered device or contact an administrator." — same cause, seen at the clock instead of at launch. Same fix.
• "Device verification required" with a Retry button — that's a connection problem, not another phone. Retry on better signal.