# Reported issues for umbryn-mcp

Pod holds 10 of 10 problems reported by people outside the maintainer team. Issues filed by the project's own owners, members and collaborators are excluded entirely — a maintainer's release checklist is not a warning to a prospective user.

Back to [umbryn-mcp](/mcp/umbryn-mcp).

## Most discussed

### Add a US Passport number recognizer (context-gated, no checksum)

## Add a recognizer: US Passport number

**Great first contribution!** This is one of the friendliest recognizers to add: there's no check-digit math to implement, so it's mostly a regex + a context gate + tests. Everything you need to implement it is spelled out below — no further research required.

### What & why

A US passport number is a nine-character government identifier that shows up in travel records, KYC/onboarding forms, visa paperwork, and support tickets — exactly the kind of PII t

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/19) · 2026-07-06 · open · 3 comments

### Add an Australian Tax File Number (TFN) recognizer (mod-11 weighted checksum)

## Add an Australian Tax File Number (TFN) recognizer

**Great first issue!** This is a self-contained recognizer with a real (and satisfying) check digit, so it follows the exact same shape as the UK NHS and Canadian SIN recognizers already in the tree. If you've been looking for a first PR here, this is a good one to claim.

### What & why

A **Tax File Number (TFN)** is the personal identifier the Australian Taxation Office issues to individuals and organisations — the Australian equivalent o

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/18) · 2026-07-06 · open · 2 comments

### Add an IBAN (International Bank Account Number) recognizer

## What & why

The default (zero-dependency) engine detects clinical identifiers and common PII, but it does **not** detect **IBANs** (International Bank Account Numbers). IBANs are financial PII that regularly appear in healthcare billing, insurance, and patient-payment text, so they belong in the redaction set. Presidio's engine already ships an `IBAN_CODE` recognizer, but the default regex engine has no equivalent — so a user on the zero-dependency default gets no IBAN coverage. This issue cl

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/10) · 2026-07-04 · closed · 1 comment

### Add a US Driver's License number recognizer (context-gated starter)

## What & why

Add a recognizer for **US Driver's License (DL) numbers** to the default (zero-dependency) engine. A DL number is a direct HIPAA identifier (45 CFR §164.514(b)(2)(i)(J) — "certificate/license numbers") and shows up constantly in intake forms, incident notes, and identity-verification text, so redacting it before text reaches an LLM is high-value.

**This is deliberately a *starter* recognizer.** US DL formats vary by state and there is **no single nationwide format and no universa

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/9) · 2026-07-04 · closed · 1 comment

### Add a Legacy Medicare HICN (Health Insurance Claim Number) recognizer

## What & why

Add a recognizer for the **legacy Medicare HICN** (Health Insurance Claim Number) — the SSN-based Medicare identifier that was printed on Medicare cards before the [MBI transition](https://www.cms.gov/training-education/partner-outreach-resources/new-medicare-card/medical-beneficiary-identifiers-mbis) completed on 2020-01-01. HICNs no longer appear on new cards, but they are **still all over historical records** — old claims, EOBs, redetermination notices, legacy EHR exports, spre

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/8) · 2026-07-04 · closed · 1 comment

### Add a US ITIN (Individual Taxpayer Identification Number) recognizer

## What & why

An **ITIN** (Individual Taxpayer Identification Number) is a US tax ID the IRS issues to people who need a taxpayer identifier but are not eligible for an SSN. It is a direct-identifier under HIPAA's Safe Harbor "account/certificate/license number" and "any other unique identifying number" clauses, and it appears in exactly the kinds of intake, billing, and tax documents phi-redact-mcp is meant to scrub. We currently detect SSNs but **not** ITINs, so a document like `Taxpayer ITIN

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/7) · 2026-07-04 · closed · 1 comment

### Add a Canadian Social Insurance Number (SIN) recognizer

## What & why

Add a recognizer for the **Canadian Social Insurance Number (SIN)** — the 9-digit identifier Service Canada issues for tax, benefits, and employment. It is squarely PII (and PHI in Canadian clinical/insurance contexts), so it belongs in the default engine alongside US_SSN. It has a **Luhn mod-10 check digit**, so we can validate it and give it a high, precise score rather than relying on shape alone.

Good news for the implementer: the SIN's check digit is a **plain Luhn over all 

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/6) · 2026-07-04 · closed · 1 comment

### Add a UK NHS Number recognizer (10 digits, mod-11 check digit)

## What & why

The NHS Number is the unique patient identifier used across the UK's National Health Service. It is a direct patient identifier and clearly PHI/PII, so it belongs in the default recognizer set alongside our other clinical identifiers (NPI, DEA, MBI, CLIA).

Crucially, it carries a **mod-11 check digit**, which puts it in our high-precision "checksum-backed" tier: a match that fails the check digit is *discarded outright*, not merely down-scored. This lets us score it high on shape

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/5) · 2026-07-04 · closed · 1 comment

## Most recent

### Add a Brazilian CPF recognizer (11 digits, two mod-11 check digits)

## Add a Brazilian CPF recognizer (checksum-backed)

**Good first issue** · Adds one new checksum-backed recognizer. No changes to the engine or public API — just a regex, a small validator, an entity constant, and tests. A great way to learn the recognizer pattern end to end.

### What & why

The **CPF** (*Cadastro de Pessoas Físicas*) is Brazil's individual taxpayer registry number, issued by the Receita Federal (the federal tax authority). It's the primary national identifier for a private in

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/17) · 2026-07-06 · open · 0 comments

### Add a Spanish DNI/NIE recognizer (mod-23 check letter)

## What & why

The **Spanish DNI** (*Documento Nacional de Identidad*) is the national ID number for Spanish citizens; the **NIE** (*Número de Identidad de Extranjero*) is its equivalent for foreign residents. Both are ubiquitous personal identifiers across Spanish healthcare, tax, and banking records, and both are exactly the kind of national-ID PII this project aims to redact. They're a great fit for our precision-first approach because each carries a **mod-23 check letter**: we can run a vali

[Read the thread](https://github.com/Rinava/umbryn-mcp/issues/16) · 2026-07-06 · open · 0 comments

The remaining reports are on [the project's issue tracker](https://github.com/Rinava/umbryn-mcp/issues).