Entering the code incorrectly 5 times in a row will block making of any transactions. In order to unblock the transactions, citizen should send a ticket to the Game Support department for further assistance. The security code will only be requested while making actions stated above. Any other requests for the code may compromise the security of the account.
Please note: If your account gets hacked/phished and your safety code is NOT set, in cases where your companies/training grounds get downgraded you will NOT get any support/refund for your lost goods.
"Unfortunately we cannot offer you support in this case because you didn't activated your safety code. "
So if you haven't have one set yet, we suggest you do it right away! You can set your safety code on your edit profile page. Oh and a protip from the team; If you tend to forget such codes, write it down on a piece of paper and put it under an object you don't move a lot (like a printer).