Online banking

Online banking

Showing results for 
Search instead for 
Did you mean: 

Online Banking

What is a Temporary Security Number and when do I use it?

A Temporary Security Number is a code we use as an additional security measure to confirm your identity if:


  • you're registering for Online Banking for the first time


  • you've forgotten your login details


  • you're using a browser on a computer or mobile device we don't recognise and we don't have your up to date mobile phone number.


We'll send the Temporary Security Number to you by text message, if we have your up to date mobile phone number. If we don't, we'll send it by post and you'll have to wait for it to arrive before you can log in to Online Banking.


When you receive your Temporary Security Number return to the Registration or Login screen. You'll be asked to enter the Temporary Security Number in full to complete registration or reset your login details.


Your Temporary Security Number is valid for 30 days from the date it was requested and can only be used once. If it expires, you'll need to contact us to get a new one.

Version History
Revision #
4 of 5
Last update:
‎28-04-2015 11:47 AM
Updated by:

Hi @Hellokitty, if you get locked out from online banking or need a temporary security number, please send a private message to @CET so we can get it reset for you.


Please note: don't include the @ symbol when putting in the contact details via private message, just CET.


In the message explaining your situation, include your name, date of birth and postcode.


For details like your DOB and postcode we ask for you to format it with additional spaces, i.e. A B 1 2 C D and 2 4 1 0 2 0 1 6, otherwise the information is removed by the system. 




I received two texts, one for my when registering you will need Temporary Security number and the second one is  Temporary Security number.

How to do register online banking as I don't have the sort code and account number   


I just went through that whole process for them to go "unfortunately we can't offer you an account" **bleep**? 


What a mess!

Dear Tesco staff, please fix this. You are driving customers mad and driving them away.


How do I request a TSN? I keep reading that I have to send a message to @CET (but without the @ symbol) but don't even know what the hell that means?? 

@stevenling2017 - Your sort code and account number will be detailed on any documents we've sent or are yet to send if a new customer. I hope this helps!

@antmanuk - Can you give us more information on what is needing fixed, and we'll do our best to resolve any problems you've encountered please?

@Paulmolloy - You'll need to search for CET as a user and then send a private message. Alternatively, you can contact us via Facebook by searching Tesco Bank or Twitter by using our @tescobankhelp handle. If sending any personal details then please ensure you do this privately. 


Hi there, I am basically locked out of my Tesco online app and website. I have tried using the temporary passcode that they send to your mobile but that hasn't worked either. 

Sorry to hear that @Paulmolloy. I can see that we've now sent a code to your home address. Let us know how you get on!


Forgot password and security number 

Hi @Craigwatkins71, if you follow the steps Ross mentioned at the top of this page, we'll be able to help reset your details :-)