Spain Tax Identification Number

Detects Spain 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

high

Confidence justification

High confidence: eight digits followed by a single letter is a distinctive format for Spanish NIF/DNI numbers.

Detection quality

Verified

Jurisdictions

es, eu

Regulations

GDPR

Data categories

pii, financial, government-id

Scope

narrow

Risk rating

5

Platform compatibility

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

Pattern

\b\d{8}[A-Z]\b

Corroborative evidence keywords

NIF, número de identificación fiscal, DNI, CIF, Hacienda, tax identification, [object Object], tax identification number, tax number, tax return, [object Object], [object Object], tax ID, inland revenue, taxpayer identification, αριθμός φορολογικού μητρώου, ΑΦΜ, φορολογικός, Abgabenkontonummer, adóazonosító (+26 more)

Proximity: 300 characters

Should match

• 12345678A — Spanish NIF with letter suffix
• 98765432Z — Spanish tax identification number
• 11223344M — Spanish DNI/NIF format

Should not match

• 1234567A — Only 7 digits, too short for Spanish NIF
• 123456789A — 9 digits with letter, exceeds Spanish 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

• Spain Tax Identification Number entity definition - Microsoft Learn