> ## Documentation Index > Fetch the complete documentation index at: https://scubazenapp.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Sign in > Sign in with an emailed link or a 6-digit code. There are no passwords; your first sign-in creates your account. To sign in, type your email and tap **email me a sign-in link**. SCUBAzen emails you a link and a 6-digit code: tap the link on the same phone, or type the code into the app. There are no passwords, and the same page works for new and returning divers. If the address has never been used, your first sign-in creates the account. ## Sign in with the link Type your address in the email field and tap **email me a sign-in link**. The button briefly reads **sent**, then the page changes to **check your email**: "tap the link we sent to" your address. The email comes from SCUBAzen ([signin@scubazenapp.com](mailto:signin@scubazenapp.com)) with the subject "your SCUBAzen sign-in link". On iPhone, **open mail** opens your mail app. On Android there is no such button, so open your mail app yourself. Tap **sign in to SCUBAzen** in the email. SCUBAzen opens and shows **signing you in**. A new account goes into [setup](/docs/get-started/setup), picking up at the step you reached if you started it earlier. An existing account goes to [home](/docs/get-started/home). If SCUBAzen is closed while you are in your mail app, it comes back to **check your email** when you reopen it, for as long as that email is still usable (15 minutes). ## Sign in with the code Use the code when the email is on another device (a laptop, a tablet) or when tapping the link does not open the app. On **check your email**, under **other ways in**, tap **enter the code instead**. The page reads **enter the code**: "the 6 digits under the link in our email to" your address. The app signs in as soon as the sixth digit is in. You can also tap **sign in**. On iPhone, the keyboard may offer to fill the code from Mail. ## Link or code: the rules | | Link | Code | | - | - | - | | How long it works | 15 minutes, once | 15 minutes, once | | Where it works | Only on the phone that asked for the email | In the app on any phone, wherever you read the email | | After a newer email | Still works until its 15 minutes are up | Stops working; only the newest email's code is accepted | The email says this too: asking for another email replaces its code, but its link keeps working. Using either one spends both: once you sign in with the link, that email's code no longer works, and the other way round. ## Send another email or change the address Under **other ways in** on the waiting screens: * **send it again** sends a fresh email to the same address. After each email it counts down, "send again in 30 s", before you can ask again. * **use a different email** takes you back to the email field with your address still in it, so you can fix a typo. SCUBAzen also limits how many emails one address and one network can be sent in an hour, and how many it sends in a day overall. If you hit a sending limit, you see "too many emails for now. try again in an hour, or tomorrow if it still won't send." Checking codes and links has a separate limit: too many failed sign-ins from one network in an hour. If you hit it, you see "too many failed sign-ins from this network. switch between wifi and mobile data, or wait up to an hour." On shared wifi, such as a dive resort's, other people's failed sign-ins count toward it, so switching to mobile data usually gets you through. ## If something goes wrong The page says "a link works once, for 15 minutes." The link was already used or is more than 15 minutes old. Tap **send a new link**, or **enter the code instead** if that email's code is still within its 15 minutes and unused. Links only work on the phone that asked for them. Tap **enter the code instead** and type the code from the same email. If this phone never asked for an email, the page first asks which address the email went to. You can also tap **send a new link** to have a fresh email sent from this phone. If the page says "check your connection and try again.", the app could not finish checking the link. Tap **retry** once you have a connection, or **back to sign in** to start again. If it says "too many failed sign-ins from this network. switch between wifi and mobile data, or wait up to an hour.", your connection is fine but your network hit the hourly limit. Switch between wifi and mobile data and tap **retry**. A link only works for 15 minutes, so if you wait instead, the link may have expired by then; the page then offers **send a new link**. The full message is "that code isn't right. check it against the newest email from us." If you asked for more than one email, only the code in the newest one works. The code is more than 15 minutes old or was already used. Tap **send it again** for a new email. The message is "too many tries. codes are paused for this address for up to a day. send a new email and tap its link on this phone." After 10 wrong codes for one email address in 24 hours, SCUBAzen stops accepting codes for that address until the 24 hours have passed. A new email does not reopen codes in that time. The link in a new email still works, so ask for one on the phone you want to sign in on and tap the link there. Check your spam or junk folder for mail from [signin@scubazenapp.com](mailto:signin@scubazenapp.com). Check that the address on **check your email** is right; if not, tap **use a different email**. Then tap **send it again**. Both mean the app could not reach the server. Check your connection and try again. "couldn't send the email" means no email went out; "couldn't reach SCUBAzen" means the email you have is still good, but the check did not happen. If the app reached SCUBAzen but the email still failed to go out, you see "we couldn't send the email. try again in a little while." The problem is on our side, not your connection. Wait a little, then tap **send it again** (or **email me a sign-in link**). If you tap a sign-in link while you're already signed in, the link is not used, even if it was for a different address. The app opens where it normally would and tells you: "you're already signed in as" your address, "so that link wasn't used. to sign in as someone else, sign out first." To switch accounts, [sign out](/docs/settings/sign-out), then tap the link again within its 15 minutes or ask for a new email. Still stuck? See [Troubleshooting](/docs/help/troubleshooting). ## Change the app language The language picker sits at the foot of the sign-in page, under the email button. It lists English, Deutsch, Español, Français, Nederlands, Polski and Русский. Your choice is remembered on this phone, including after you sign out. Once you're signed in, change it from **language** in settings, under **app**. It's the same list. See [Settings](/docs/settings/index#language). ## Related * [Install SCUBAzen](/docs/get-started/install) * [Set up SCUBAzen](/docs/get-started/setup) * [Troubleshooting](/docs/help/troubleshooting) * [Your account](/docs/settings/account) ## Related topics - [Sign out](/docs/settings/sign-out.md) - [Hand signals](/docs/help/hand-signals.md) - [Troubleshooting](/docs/help/troubleshooting.md) - [Delete your account](/docs/settings/delete-account.md) - [Install SCUBAzen](/docs/get-started/install.md) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.