EU National IDs Your PII Tool Misses
Tax ID numbers are very sensitive. They appear on payslips, tax forms, and bank applications. If they leak, they enable fraud and identity theft.
GDPR treats them as personal data. Their real-world risk is high. Every EU country uses its own national identifier format. Most PII tools were built for the US or UK market. They find SSNs and NINOs easily. They often miss the Steueridentifikationsnummer, Codice Fiscale, and BSN. These are formats European teams process every day.
The EU Tax ID Landscape
Each EU country has its own format. Here are the most common ones.
Germany — Steueridentifikationsnummer
The Steuer-ID is 11 digits. It is assigned at birth. The first digit is 1–9 (never 0). No three identical digits appear in a row. Example: 12345678901. The Steuernummer is also used: 10–11 digits, format varies by state.
France — Numéro fiscal de référence
The SPI is 13 digits. DGFiP, the French tax authority, issues it. On tax documents it appears as "Identifiant fiscal."
Italy — Codice Fiscale
The Codice Fiscale is 16 alphanumeric characters. It encodes surname, given name, birth year, birth month, birth day, and municipality. Example: RSSMRA85M01H501Z. The format is verifiable by checksum.
Spain — NIF and NIE
Spanish nationals use a DNI number plus a check letter: 8 digits + letter, e.g. 12345678A. Foreign residents use the NIE: prefix X/Y/Z + 7 digits + check letter, e.g. X1234567A. Entities use the CIF: letter + 8 digits, e.g. B12345678.
Netherlands — BSN
The BSN (Burgerservicenummer) is 9 digits. It uses the 11-proef check-digit algorithm. It is very common in payroll and benefits documents.
Poland — PESEL
The PESEL is 11 digits. The first 6 encode the date of birth. The last digits encode gender and sequence.
Belgium — Numéro de registre national
The RN is 11 digits. It encodes date of birth, sequence, and check digits.
Portugal — NIF
The Portuguese NIF (Número de Identificação Fiscal) is 9 digits with a check digit. The abbreviation is the same as Spain's NIF but the format is different.
Sweden — Personnummer
The Personnummer is 10 or 12 digits. It encodes date of birth and a sequence number. Formats: YYYYMMDD-XXXX or YYMMDD-XXXX.
Finland — Henkilötunnus
The HETU is 11 characters. It encodes date, a separator, a sequence, and a check character. Format: DDMMYY-XXXC.
What Standard Tools Miss
US and UK tools include these patterns by default:
- US SSN (XXX-XX-XXXX).
- UK NINO (XX 99 99 99 X).
- US passport numbers.
- US driver's license patterns.
- Major credit card numbers.
EU national identifiers are often absent. Tools built on Presidio's default recognizer set miss them. Without EU-specific extensions, there is no EU coverage.
A Real Compliance Gap
A German payroll firm serves 500 client companies. Its workflow removes names, emails, IBANs, and phone numbers. But it misses German Steueridentifikationsnummern. That format was never in the standard setup.
A DPA audit finds unredacted Steuer-IDs in payslip PDFs. The firm faces remediation costs for past documents. It faces DPA enforcement under GDPR Article 83. It faces contractual liability to its clients.
The gap was not found by the firm. The regulator found it first.
See our GDPR conformance guide to run your own coverage check.
Priority Order for EU Coverage
Add identifier patterns in this order if you operate across multiple EU countries.
Tier 1 — Highest volume:
- Germany: Steueridentifikationsnummer.
- France: Numéro fiscal.
- Italy: Codice Fiscale.
- Spain: NIF/NIE.
- Netherlands: BSN.
Tier 2 — Significant but smaller markets:
- Poland: PESEL.
- Belgium: RN.
- Sweden: Personnummer.
- Portugal: NIF.
- Austria: Sozialversicherungsnummer.
Tier 3 — Specific use cases:
The remaining 17 EU member states. Add based on where your team processes data.
Adding the Steueridentifikationsnummer
The German Steuer-ID is the best first pattern to add. Its format is clear and well-documented.
The Steuer-ID is 11 digits. The first digit is 1–9. No three identical digits appear in a row. A custom algorithm validates the check digit.
Plain-language description for pattern generation: "German tax numbers: 11 digits. First digit is 1–9. The other 10 digits may include zeros."
After generating the pattern, test it against German payslips and tax certificates. Check the detection rate and false positive rate. Deploy only after validation passes.
Add the pattern to your German-language preset. For mixed-language document sets, pair it with language detection. This applies the right patterns to the right documents.
One Preset or Many?
Option 1 — Country-specific presets:
Create one preset per country. Route documents by origin. This gives a lower false positive rate. It requires more routing logic.
Option 2 — Combined EU preset:
Create one preset with all EU identifier patterns active. This is simpler to run. It has a higher false positive risk on generic text. It works well when identifiers are expected throughout the document.
For payroll documents: use Option 1 with routing by origin. For mixed document sets: use Option 2 with threshold tuning.
See the security and compliance overview for how preset configuration fits into a full compliance workflow.
Close the Gap Before the Audit
GDPR applies the same way in every EU member state. US-built tools often do not. The Codice Fiscale, BSN, and Steuer-ID carry the same risk as an SSN. They appear just as often in shared documents.
Custom entity patterns close the detection gap in hours. Add a Steuer-ID pattern. Test it against sample German payslips. Deploy it to all workflows. No waiting for the tool vendor. No DPA audit needed to find the gap.
anonym.legal lets you add custom entity types through the preset configuration interface. Patterns are validated against your sample documents before deployment.
Sources
- Bundeszentralamt für Steuern: Steueridentifikationsnummer. VERIFIED-EXTERNAL.
- GDPR Articles 4, 9, 32 — gdpr-info.eu. VERIFIED-EXTERNAL.
- EDPB: Guidelines on Supervisory Authority Competence. VERIFIED-EXTERNAL.