Why do codes change every 30 seconds?

TOTP mixes your secret key with the current time in 30-second windows, so a code that leaks is useless almost immediately.

Does the app need internet to make correct codes?

No, but it does need the correct time. Keeping Set Automatically on is what keeps your device's clock accurate.

Why are my 2FA codes not working?

Codes are calculated from your account's secret key and the current time, so if your device's clock drifts even by a minute the codes won't match what the server expects.

Fix rejected codes

On your iPhone, open Settings › General › Date & Time and turn on Set Automatically.
Check your time zone is correct.
Go back to Authenticator App and try a freshly generated code.
Type the code quickly — each one is only valid for about 30 seconds.
Make sure you're using the code for the right account if you have several similar ones.

Still refused?

Confirm the account was added with the correct setup key — a mistyped key produces valid-looking but wrong codes.
If you enrolled the account twice, remove the stale copy.
As a last resort, use the service's recovery codes and set 2FA up again.

FAQ

Why do codes change every 30 seconds?: TOTP mixes your secret key with the current time in 30-second windows, so a code that leaks is useless almost immediately.
Does the app need internet to make correct codes?: No, but it does need the correct time. Keeping Set Automatically on is what keeps your device's clock accurate.

Keep your 2FA codes in one secure place

Authenticator App - Novaz generates your codes offline, backs them up encrypted to your own iCloud, and locks behind Face ID — free and ad-free.

Download on the App Store

Related guides

Set up 2FA on your accounts

Step-by-step guides for the services people secure first.

Browse all setup guides or check whether a service supports 2FA.