---
title: "List malformed participant identifiers"
method: GET
path: "/v1/id-quality/malformed"
tags: ["ID Quality"]
---

# List malformed participant identifiers

`GET /v1/id-quality/malformed`

## Request

- Base URL: `https://api.peppolstatus.com`
- URL: `https://api.peppolstatus.com/v1/id-quality/malformed`
- Auth: one of:
  - HTTP bearer
  - API key in header `X-API-Key`

The individual identifiers that failed their scheme's structural rule, keyset-paginated on (scheme, value). The first page's `meta.facets` gives scheme and reason counts over the filtered set.

## Query parameters

- `scheme` string
- `reason` 'length' | 'charset' | 'check-digit'
- `q` string
- `smp` string
- `limit` integer
- `cursor` string

## Response `200`

A page of malformed identifiers with scheme/reason facets.

- IdQualityMalformedPage: A keyset page of malformed identifiers with first-page facets.
  - `items` IdQualityViolation[], required
    - `scheme` string, required
    - `value` string, required
    - `participant_id` string, required: Full canonical participant id, e.g. `iso6523-actorid-upis::0208:1039563252`.
    - `rule` string, required
    - `reason` 'length' | 'charset' | 'check-digit', required
    - `detail` string, nullable, required
    - `first_detected_at` string, date-time, required
    - `last_checked_at` string, date-time, required
    - `smp` string, nullable, required: Serving SMP hostname, or null.
    - `ap_seat_id` string, nullable, required: Serving AP seat id, or null.
    - `ap_provider` string, nullable, required: Display name of the serving AP seat's provider, or null.
  - `next_cursor` string, nullable, required: Opaque cursor for the next page, or null on the last page.
  - `meta` object, required
    - `facets` object, required: Value→count maps honouring the other active filters.
      - `scheme` object, required
      - `reason` object, required
      - `smp` object, required: Top-50 serving SMP hostnames → malformed-id count.

## Other responses

- `400`: An invalid `reason`, `limit` or `cursor`.

---

[API](https://skmtc.dev/peppolstatus/apis/peppolstatus-api.md) · [All operations](https://skmtc.dev/peppolstatus/apis/peppolstatus-api/llms.txt) · [OpenAPI document](https://skmtc.dev/peppolstatus/apis/peppolstatus-api/revisions/7e74fb32f23c?raw)