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

7

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, TIN, tax identification number, tax number, tax return, IRD, tax ID, inland revenue, taxpayer identification, αριθμός φορολογικού μητρώου, ΑΦΜ, φορολογικός, Abgabenkontonummer, adóazonosító, adószám (+20 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