How to know Customer ID/Unique ID BSNL without telephone bill ?

Hi,
I dont have my BSNL landline bill.
But I want to know the customer ID/unique ID.
Can I know it using landline number?

I think it is not possible to know it without BILL but you can go to local BSNL office and can get duplicate bill for your number easily.

Hi,
I dont have my BSNL landline bill.
But I want to know the customer ID/unique ID.
Can I know it using landline number?