Are mobile broadband numbers recycled?

Recently, we’ve been making heavy use of a mi-fi unit (see some of our adventures here). It’s currently fitted with a mobile broadband SIM from French telcom SFR.

In addition to net access, you also get SMS text messaging. And since using the SFR SIM we’ve been getting a weekly bank account update.

Only it’s not for our account.

The SMS message is being sent by BNP Paribas - and we don’t have an account with them. Each message shows the current account balance, plus any ‘mouvements’ (deposits and withdrawals) during the week. There’s no other identifying info as far as I can remember (I delete the messages immediately).

Why is this happening? I can think of two possible reasons.

The number associated with my SIM might have been used before, owned by the bank account holder.

Or the bank account holder, when setting up SMS alerts, gave the wrong number. Perhaps my number is very close to his/hers. And BNP Paribas has not implemented any checking procedures to verify the numbers given by clients.

I don’t much like either option.