Portugal Tax Identification Number

Detects Portugal Tax Identification Number patterns. This pattern is based on a Microsoft Purview built-in sensitive information type. Due to the numeric format, corroborative evidence keywords are essential for reliable detection.

Type

regex

Engine

universal

Confidence

medium

Confidence justification

Medium confidence: nine-digit numbers are common. Portuguese NIF keywords like 'NIF' or 'contribuinte' are required for reliable detection.

Detection quality

Verified

Jurisdictions

pt, eu

Regulations

GDPR

Data categories

pii, financial, government-id

Scope

narrow

Risk rating

7

Platform compatibility

Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Compatible

Pattern

\b\d{9}\b

Corroborative evidence keywords

NIF, número de identificação fiscal, contribuinte, tax identification, finanças, TIN, tax identification number, tax number, tax return, IRD, tax ID, inland revenue, taxpayer identification, αριθμός φορολογικού μητρώου, ΑΦΜ, φορολογικός, Abgabenkontonummer, adóazonosító, adószám, belastingnummer (+19 more)

Proximity: 300 characters

Should match

• 123456789 — Nine-digit Portuguese NIF
• 987654321 — Portuguese tax identification number
• 112233445 — Portuguese NIF format

Should not match

• 12345678 — Eight digits, too short for Portuguese NIF
• 1234567890 — Ten digits, exceeds Portuguese NIF format

Known false positives

• Generic numeric sequences in non-tax contexts such as reference numbers or account identifiers Mitigation: Require corroborative evidence keywords within the proximity window to distinguish tax identifiers from general numeric data.
• Numbers from other identification schemes with similar digit patterns Mitigation: Layer with jurisdiction-specific detection to prioritise matches in tax-related documents and cross-reference with other identifier types.

References

• Portugal Tax Identification Number entity definition - Microsoft Learn