How do the first three digits of a mobile number identify the operator?

Each mobile operator in Bangladesh is allocated specific prefixes, so the first three digits identify the network. According to published sources the allocation is:

• 017 and 013 — Grameenphone
• 018 — Robi
• 019 and 014 — Banglalink
• 016 — Airtel
• 015 — Teletalk

Having more than one is straightforward: as subscribers grow, a prefix runs out. Each allows only a finite set of numbers, so a new one is allocated when demand rises. That is why longer-standing subscribers usually have the older prefix.

🚨 There is an important exception: because number portability lets you change operator while keeping your number, the prefix is no longer a guaranteed indicator. Someone with an 017 number may have moved to another network. So if you need certainty before dialling a code, the app or the helpline is better. The prefix remains a good first guess — most numbers have never been ported — but treat it as a guess rather than a fact, particularly for a number you have been given rather than one you have used for years.

Sources:

• Bangladesh Unified SIM Codes compilation