India Phone Number

Detects Indian mobile telephone numbers per the Department of Telecommunications' National Numbering Plan 2003 (as amended): 10-digit mobile numbers with a constrained leading digit (6-9, expanded from 7-9 to include 6 when DoT authorized 6-series allocation in 2017), in both the bare domestic form and the +91 international form (leading 0 dropped). Landline/STD (Subscriber Trunk Dialling) numbers are intentionally out of scope: STD codes vary 2-8 digits with no verified structural rule constraining their leading digit, so a regex loose enough to cover them (just "10 digits after a leading 0") would be barely tighter than matching any 11-digit sequence — far too high a digit-collision risk to ship without a genuinely verified constraint. See false_positives.

Type: regex
Engine: universal
Confidence: medium
Confidence justification: Medium confidence: the mobile leading-digit constraint (6-9) narrows the format, but Indian mobile numbers carry no checksum and a bare 10-digit mobile-shaped sequence is still a high digit-collision format (any 10-digit number starting 6-9 is common). Per the phone-family convention set by au-fixed-line-telephone (every tier requires positive corroborative evidence; high digit-collision formats never get a zero-evidence tier), both the domestic and +91 international sub-regexes are evidence-gated at every tier: 75 requires generic phone-context evidence and 85 requires country-specific phone keywords with template/noise exclusion. The literal +91 prefix improves precision when present but is not by itself sufficient gating. Unlike NANP (555-01XX) and the UK (Ofcom drama numbers), no DoT/TRAI-published fictional/test number range exists for India — this was confirmed by web research and is documented rather than invented; test_cases below use an illustrative, clearly-non-official descending-digit placeholder instead.
Jurisdictions: in
Regulations: DPDPA, IT Act 2000 (India), TCCCPR
Frameworks: ISO 27001, ISO 27701, SOC 2
Data categories: pii, contact-information
Scope: narrow
Risk rating: 5
Platform compatibility: Purview: Compatible, GCP DLP: Unsupported, Macie: Unsupported, Zscaler: Compatible, Palo Alto: Unsupported, Netskope: Unsupported

Pattern

(?<!\d)(?:\+91[\s.-]?[6-9]\d{4}[\s.-]?\d{5}|[6-9]\d{4}[\s.-]?\d{5})(?!\d)

Corroborative evidence keywords

phone, mobile, call, text, contact number, Indian mobile number, WhatsApp number, call me at, cell, telephone, tel, dial, text me, text message, [object Object], WhatsApp, voicemail, phone number, mobile number, landline

Proximity: 300 characters

Should match

Call me at 98765 43210 — Domestic mobile, leading digit 9, illustrative descending-digit placeholder, common 5+5 spaced grouping
WhatsApp number: 9123456789 — Domestic mobile, leading digit 9, bare digits with no separator
Contact: +91 9876543210 — International +91 mobile form, leading 0 dropped, contiguous digits
Mobile: 6123456789 — Domestic mobile, leading digit 6 — the range DoT opened in 2017 for Jio 6-series allocation

Should not match

5234567890 — Leading digit 5 is not in the valid 6-9 mobile range
987654321 — Only 9 digits — one short of the required 10
1800 123 4567 — Toll-free 1800 number — does not match the mobile leading-digit range
+91 5876543210 — International form but leading digit 5 (after the country code) is not in the valid 6-9 mobile range

Known false positives

A bare 10-digit mobile-shaped sequence (leading digit 6-9) is a high digit-collision format — it can coincidentally match invoice numbers, order numbers, or other structured identifiers of the same length and leading-digit distribution. Mitigation: Every tier — for both the domestic and +91 international sub-regexes — requires positive phone-context or country-specific evidence within 300 characters; no zero-evidence tier exists, so a bare digit run without corroborating context never fires at any confidence level.
No official DoT/TRAI fictional or test number range exists for India (confirmed by web research, unlike NANP's 555-01XX or Ofcom's drama numbers), so an illustrative descending-digit test value was used instead of an authoritative reserved range. Mitigation: Test values use clearly non-representative digit patterns; deployers should substitute their own tenant's synthetic test data for live validation rather than relying on a non-existent official reserved range.
Landline/STD numbers are out of scope for this initial release because India's STD codes vary 2-8 digits with no verified leading-digit constraint, so this pattern will not detect landline numbers at all (a false negative, not a false positive, but noted here for completeness). Mitigation: A future revision could add STD/landline coverage if a genuinely verifiable structural constraint (beyond "10 digits after a leading 0") is confirmed from a primary DoT/TRAI source.