Short answer: the SNGPL consumer number has exactly 11 digits. Websites saying 10, 13 or 14 digits are wrong — and we can prove it from SNGPL's own form.
If your number is accepted here, it is the right length: the official system only works with 11 digits.
Madad: Apna 11-digit consumer number kisi purani SNGPL bill ke upar "Consumer No" ke samne milta hai. Number likh kar Check Bill dabayen — bill yahin isi page par khud khul jayega, aam tor par chand seconds me. Kabhi kabhar backup ke tor par aik chhota security code likhna par sakta hai.
On SNGPL's official bill page, the consumer number box is built with a hard limit: the form's own code sets the field to a maximum of 11 characters and a pattern of exactly 11 digits. Type a 12th digit and the official form itself refuses it. The SSGC form, for comparison, is built for exactly 10 digits. These are not opinions — they are the rules coded into the companies' own systems, and they match the numbers printed on real bills.
Also wrong for SNGPL. 10 digits is the SSGC customer number (Sindh and Baluchistan). No SNGPL document uses a 13-digit consumer number. If a website cannot get the digit count right, be careful trusting its tariff tables too — use the OGRA tariff page here instead.