Australian Number Plate

Detects five implemented Australian standard number-plate shapes for NSW, Victoria, Queensland, South Australia, and Western Australia. It does not validate issuance and excludes personalised plate formats; registration and transport-agency evidence controls enforcement.

Type: regex
Engine: universal
Confidence: low
Confidence justification: Low confidence: short alphanumeric plate formats can easily match product codes, abbreviations, and other non-vehicle identifiers. Corroborative evidence keywords such as registration, rego, or number plate are essential for reliable detection.
Detection quality: Partial
Jurisdictions: au
Regulations: Information Privacy Act 2009 (Qld), NDB Scheme (Cth), Privacy Act 1988 (Cth)
Frameworks: ISO 27001, ISO 27701
Data categories: location, pii
Scope: wide
Risk rating: 4
Platform compatibility: Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Unsupported

Pattern

\b(?:[A-Z]{2}[\s\-]?\d{2}[\s\-]?[A-Z]{2}|\d[A-Z]{2}[\s\-]?\d{3}|\d{3}[\s\-]?[A-Z]{2}[\s\-]?\d|S\d{3}[\s\-]?[A-Z]{3}|1[A-Z]{3}[\s\-]?\d{3})\b

Corroborative evidence keywords

registration, rego, number plate, address, age, birthday, citizenship, city, date of birth, [object Object], email, ethnicity, fax, first name, full name, gender, given name, last name, maiden name, middle name (+12 more)

Proximity: 500 characters

Should match

AB12CD — Low-tier probe - bare NSW-shaped candidate
Vehicle registration: 1AB234 — Medium-tier probe - registration context without a transport agency
TMR vehicle registration plate: 123AB4 — High-tier probe - Queensland shape with registration and agency context

Should not match

ABC123 — Three letters followed by three digits (not a valid format)
A1B2C3 — Alternating letters and digits (not a valid format)
1234AB — Four digits followed by two letters (not a valid format)
Model code AB12CD for the replacement assembly — Plate-shaped product code with explicit model/code context
Training example: TMR vehicle registration plate 123AB4 — Structurally complete but explicitly framed training content

Known false positives

Common words and phrases related to au number plates appearing in policy documents, training materials, HR templates, or compliance guidelines without actual personal data. Mitigation: Require corroborative evidence keywords within the proximity window to confirm sensitive data context rather than general discussion.
In Australian English, similar terminology used in formal or administrative contexts (education, professional documentation) that does not constitute sensitive data collection. Mitigation: Layer with additional contextual signals such as structured identifiers, form fields, or database column headers to distinguish sensitive records from general references.
High-frequency pattern matches in large document corpora due to broad regex anchors. Expected match rate is significantly higher than specific identifier patterns. Mitigation: Tune confidence thresholds for bulk scanning. Consider using this pattern primarily as a pre-filter with secondary validation.