🇮🇳 India Phone Number Format

Indian mobile numbers are exactly 10 digits and always start with 6, 7, 8 or 9 — written +91 98765 43210 internationally, in India’s distinctive 5+5 grouping. Landlines combine an STD area code (written with a leading 0) with a subscriber number for 10 digits total.

Indian Mobile and Landline Formats Compared

Here is how one India number is written in each of the four standards:

FormatExampleUse for
E.164 +919876543210 Databases, SMS APIs (Twilio, WhatsApp), CRMs
International +91 98765 43210 Display to a global audience, business cards
National 098765 43210 Domestic display inside India
RFC3966 tel:+91-98765-43210 Clickable tel: links on websites

From STD Codes to a Billion 10-Digit Mobiles

India runs the world’s second-largest phone network on a remarkably simple consumer rule: every mobile is ten digits, first digit 6–9. The 9-series came first; as a billion subscriptions piled up, TRAI successively opened the 8, 7 and finally 6 series. A “mobile number” field that only accepts 9xxxxxxxxx rejects hundreds of millions of valid users.

Landlines still carry the older STD geography — 011 Delhi, 022 Mumbai, 080 Bengaluru — where bigger cities got shorter codes. The leading 0 is purely a domestic trunk prefix: dialing from abroad it vanishes (+91 11 2345 6789), yet Indians habitually write numbers with it, so parsers must strip it.

Since TRAI’s January 2021 change, calls from a landline to any mobile must be prefixed with 0 even locally — a rule that surprises even Indian users and exists purely to free up numbering space for future 10-digit landlines.

Mobile Series 6–9 and STD Codes

TypePrefixesDigitsExample
Mobile 6, 7, 8, 9 10 98765 43210
Delhi landline 011 10 (incl. STD) 011 2345 6789
Mumbai landline 022 10 022 2345 6789
Toll-free 1800 11 1800 123 4567

Calling India: the +91 Rules

Calling fromDial
Within India (mobile) 98765 43210 — No prefix needed mobile-to-mobile.
From the US 011 91 98765 43210
From any mobile +91 98765 43210
  1. Enter + or your country’s exit code.
  2. Add the Indian country code 91.
  3. Drop any leading 0 from the Indian number.
  4. Dial the 10-digit mobile or STD + landline number.

TRAI Rules That Change How You Dial

  • Indian mobiles never start with 0–5; a 10-digit number starting 6–9 is the strongest signal of a valid Indian mobile.
  • The leading 0 sometimes shown on Indian numbers (098765…) is the domestic trunk prefix and must be dropped after +91.
  • TRAI changed fixed-line dialing in 2021: calling a mobile from a landline now requires the 0 prefix.
  • Indian numbers are conventionally grouped 5+5 for mobiles (98765 43210), unlike the 3-3-4 US grouping.

Frequent Mistakes with Indian Numbers

  • Writing 091 or 0091 before the number — the international form is +91 with no extra zero.
  • Keeping the leading 0 after +91 — “+91 098765 43210” is invalid; drop the trunk zero.
  • Rejecting mobiles that start with 6, 7 or 8 — only pre-2010 assumptions limit mobiles to the 9-series.
  • Grouping as 3-3-4 (US style) — Indian readers expect 98765 43210, the 5+5 split.

Format an Indian Number Now

Works with every style — 098765 43210, 98765-43210 or bare digits — and returns the +91 E.164 form WhatsApp and SMS APIs require.

Enter phone number with country code or select country below.

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India Phone Format FAQ

How do I write an Indian mobile number with country code?

Add +91 before the 10-digit mobile: +91 98765 43210, or +919876543210 in E.164. Drop any leading 0 shown in domestic format.

How many digits is an Indian phone number?

Mobiles are exactly 10 digits. Landlines also total 10 digits when you combine the STD area code (without its leading 0) and the subscriber number.

What digits do Indian mobile numbers start with?

Only 6, 7, 8 or 9. Numbers starting with other digits are landlines, services, or invalid.

Why does my Indian number show a leading 0?

The 0 is India’s domestic trunk prefix used when dialing between regions or from landlines. It is never included after +91 in international format.

How do I call India from the USA?

Dial 011 91 followed by the 10-digit number: 011 91 98765 43210. On mobiles, +91 98765 43210 works directly.

Other Country Formats