Certificates

Upload and manage PKCS#12 signing certificates for fiscal authority communication. All endpoints require authentication.

Upload a certificate

POST /v1/certificates

Uploads a PKCS#12 certificate bundle. The certificate is validated, and metadata (subject, issuer, validity dates, NIF) is extracted automatically.

Request

Multipart form data:

Field	Type	Required	Description
certificate	file	Yes	PKCS#12 (.p12/.pfx) file, max 10 MB
password	string	Yes	Password to decrypt the PKCS#12 bundle
certificate_id	string	Yes	Identifier for referencing in location config (alphanumeric, hyphens, underscores, dots)

Example

curl -X POST https://api.fiscalapi.com/v1/certificates \
  -H "Authorization: Bearer fsk_test_abc123def456..." \
  -F "certificate=@signing-cert.p12" \
  -F "password=my-cert-password" \
  -F "certificate_id=spain-prod-2026"

Response 201 Created

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "certificate_id": "spain-prod-2026",
  "subject_cn": "ACME CORP SL",
  "issuer": "AC FNMT Usuarios",
  "not_before": "2025-01-15T00:00:00Z",
  "not_after": "2027-01-15T23:59:59Z",
  "nif": "B12345674",
  "created_at": "2026-03-09T12:00:00Z"
}

Errors

Status	Error	Cause
400	certificate_id is required	Missing certificate_id field
400	invalid certificate_id format	Contains invalid characters
400	password is required	Missing password field
400	failed to read certificate file	File upload error
400	failed to decode PKCS#12 bundle	Invalid file or wrong password
409	certificate with this ID already exists	Duplicate certificate_id

---

List certificates

GET /v1/certificates

Returns all certificates for the authenticated account.

Example

curl https://api.fiscalapi.com/v1/certificates \
  -H "Authorization: Bearer fsk_test_abc123def456..."

Response 200 OK

{
  "data": [
    {
      "id": "550e8400-e29b-41d4-a716-446655440000",
      "certificate_id": "spain-prod-2026",
      "subject_cn": "ACME CORP SL",
      "issuer": "AC FNMT Usuarios",
      "not_before": "2025-01-15T00:00:00Z",
      "not_after": "2027-01-15T23:59:59Z",
      "nif": "B12345674",
      "created_at": "2026-03-09T12:00:00Z"
    }
  ]
}

---

Delete a certificate

DELETE /v1/certificates/{id}

Deletes a certificate by its certificate_id.

Path parameters

Parameter	Type	Description
id	string	The certificate_id assigned during upload

Example

curl -X DELETE https://api.fiscalapi.com/v1/certificates/spain-prod-2026 \
  -H "Authorization: Bearer fsk_test_abc123def456..."

Response 204 No Content

No response body.

Errors

Status	Error
404	certificate not found

---

Certificate metadata

Field	Type	Description
id	uuid	Internal identifier
certificate_id	string	User-assigned identifier for referencing in location config
subject_cn	string	Certificate subject common name
issuer	string	Certificate issuer
not_before	datetime	Certificate validity start
not_after	datetime	Certificate validity end
nif	string	Tax ID extracted from certificate Subject.SerialNumber (IDCES-/VATES- pattern)
created_at	datetime	Upload timestamp

PKCS#12 format

FiscalAPI requires certificates in PKCS#12 format (.p12 or .pfx files). These bundles contain:

• The signing certificate
• The private key
• Any intermediate CA certificates

Spanish tax authorities (AEAT, Basque regional authorities) issue certificates in this format. The certificate must contain a valid private key for signing fiscal documents.