What other verification question can be asked for change mobile number ?

Other verification questions can be asked:

1. Last visited station
2. Last purchase amount
3. Frequently visited station
4. Average fuel purchased
5. Email address of the old account ( if there is no transaction details in Setel, ask user to verify and show proof of Gmail: Open Gmail > Click icon at top right side > Manage your Google Account > Screenshot it > Done)
   
6. Bill statement of the old account (show old number on it)
7. Proof that can show the old account number used by the customer before
8. e-Receipt from past purchase with the old phone number

Note:/

When the user fails verification via email, FTA must call the user. Ask them another verification question on the call. .

If the customer fails all verifications, the request is canceled. Please advise the user accordingly.