Mobile Advertising ID (IDFA / GAID / AAID)

Detects mobile advertising identifiers - Apple's IDFA and Google's Advertising ID (GAID, also called AAID) - when they appear labelled with an advertising-ID keyword. These IDs are UUIDs in the canonical 8-4-4-4-12 hexadecimal form. Although resettable, advertising IDs are persistent cross-app device identifiers treated as personal data under GDPR and CCPA/CPRA, and their disclosure enables cross-context tracking and re-identification.

Type: regex
Engine: universal
Confidence: medium
Confidence justification: Medium confidence: the UUID body is generic (any v4 UUID matches the hex layout), so detection relies on an explicit advertising-ID label adjacent to the value. The label requirement keeps false positives low, but unlabelled IDFA or GAID values are intentionally not matched.
Jurisdictions: global
Regulations: GDPR, CCPA/CPRA
Frameworks: ISO 27001, ISO 27701
Data categories: pii, device-id
Scope: narrow
Platform compatibility: Purview: Compatible, GCP DLP: Unsupported, Macie: Unsupported, Zscaler: Compatible, Palo Alto: Unsupported, Netskope: Unsupported

Pattern

(?:idfa|gaid|aaid|advertising[\s_-]*id|ad[\s_-]*id)[\s:#=_-]{0,8}[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}(?![0-9a-f-])

Corroborative evidence keywords

advertising id, advertising identifier, IDFA, GAID, AAID, device id, ad tracking, mobile identifier

Proximity: 300 characters

Should match

idfa: 6d92078a-8246-4ba4-ae5b-76104861e7dc — Labelled Apple IDFA in canonical UUID form
gaid=97987bca-ae59-4c7d-94ba-ee4f19ab8c21 — Labelled Google Advertising ID (GAID)
advertising_id: 12345678-90ab-cdef-1234-567890abcdef — Labelled advertising_id with hyphenated UUID

Should not match

6d92078a-8246-4ba4-ae5b-76104861e7dc — Bare UUID with no advertising-ID label
session id: 6d92078a-8246-4ba4-ae5b — Truncated/non-UUID value behind an unrelated label
reset your advertising identifier in the device privacy settings — Prose mention of an advertising identifier with no value

Known false positives

Other UUIDs (session tokens, request IDs, correlation IDs) that happen to sit next to the word 'ad' or 'id'. Mitigation: The pattern requires a specific advertising-ID label; tighten the label list further if generic 'ad id' collides in your corpus.