India STD code lookup

What is an STD code?

Subscriber Trunk Dialing (STD) is India’s area-code plan for long-distance landline calls without an operator. Each city or SDCA has a numeric STD code assigned under DoT rules. Metros such as Delhi (011), Mumbai (022), Chennai (044), and Kolkata (033) use short codes; smaller towns often use longer prefixes.

How to dial

• From India (another STD area): 0 + STD code + subscriber number.
• International to India: +91 + STD code (no leading 0) + subscriber number.
• Local landline: dial the subscriber number only within the same STD area.

Code length

Total national significant number length is 10 digits (excluding the trunk 0). Shorter STD codes pair with longer local numbers and vice versa.

• 2-digit STD — major metros (8-digit local)
• 3–4 digit STD — cities and large towns
• 5-digit STD — smaller exchanges

Quick tips

• Mobile numbers (6–9) do not use STD codes.
• From mobile within India, prefix 0 before the STD code.
• Always drop the leading 0 when using +91 from abroad.