backupcode
nounUK /ˈbækʌp kəʊd/
US /ˈbækʌp koʊd/
A backup code is a secret number you keep to get into your account if your main way stops working.
If you lose your phone, you can use a backup code to sign in.
OTHER MEANINGS
2. A code used to restore data from a copy.
The technician entered the backup code to reload the files.
3. A second code kept in case the first one fails.
Write the backup code on paper and store it safely.
4. A code that supports a main system during an outage.
The team switched to the backup code when the main server went down.