Germany (SIGN DE)

📘Specialized API

SIGN DE is a Specialized API — purpose-built for German KassenSichV compliance, BSI-certified, and fiskaly’s most mature product. It uses a dedicated API surface with its own endpoints and resource model. For the multi-country Unified API architecture (covering France, Italy, Sweden), see The Unified API.

What you need to know

Germany has the most comprehensive fiscal compliance requirements of any fiskaly-supported country. A full German integration requires three products working together:

Product	What it does	Required?
SIGN DE	Cryptographically signs every transaction via a BSI-certified Cloud-TSS	Yes — KassenSichV
DSFINVK DE	Generates audit-ready fiscal data exports from your cash point closings	Yes — for tax audits
SUBMIT DE	Files electronic declarations to ELSTER (German tax authority interface)	Yes — since 2025
SAFE	Archives fiscal data for 10-30 years in certified data centers	Recommended

💡New to fiskaly?

Start with the Quick Start to get a signed transaction in 5 minutes. Come back here for the full picture.

What is KassenSichV?

The Kassensicherungsverordnung (KassenSichV) requires all electronic recording systems (ERS) in Germany to:

• Use a certified Technical Security System (TSS) to sign every transaction
• Maintain tamper-proof audit trails with cryptographic signatures
• Generate DSFinV-K exports for tax auditors
• Print QR codes on receipts containing the signature data

fiskaly’s Cloud-TSS is the first cloud-based TSS to achieve BSI certification, currently valid until 2033. No hardware, no local crypto modules — just API calls.

Integration effort

For PMs estimating the work:

Phase	Duration	What happens
Sandbox setup	1-2 days	Account creation, API keys, first signed transaction
SIGN DE integration	3-5 weeks	TSS provisioning, transaction signing, receipt QR codes, error handling
DSFINVK DE integration	2-3 weeks	Map POS data model to DSFINVK DE taxonomy, implement cash point closings
SUBMIT DE integration	1-2 weeks	Taxpayer registration, declaration filing
End-to-end testing	1-2 weeks	Full flow validation in sandbox
Go-live	1 week	LIVE provisioning, staged rollout, monitoring setup
Total	8-13 weeks	1-2 backend developers with POS domain experience

See the Integration Planning Guide for team requirements, dependency maps, and a rollout timeline template.

Architecture overview

Your POS System
  |
  |-- POST /auth (API key + secret) --> Bearer token (24h)
  |
  |-- PUT /tss/{id} -----------------> Create + initialize TSS (one-time per location)
  |-- PUT /tss/{id}/client/{id} -----> Create client (one per POS terminal)
  |
  |-- PUT /tss/{id}/tx/{id} ---------> Start transaction (state: ACTIVE)
  |-- PUT /tss/{id}/tx/{id} ---------> Finish transaction (state: FINISHED)
  |                                     Response includes signature + QR code data
  |
  |-- POST /dsfinvk/closings --------> Submit cash point closing data
  |-- GET  /dsfinvk/exports  --------> Generate DSFinV-K export file
  |
  |-- POST /submission/submit -------> File declaration to ELSTER

Responsibilities

Your responsibility (POS vendor)

• Integrate the fiskaly TSS into your ERS
• Ensure every transaction is signed before receipt generation
• Print QR codes containing signature data on receipts
• Generate DSFINVK DE cash point closings at end-of-day
• File declarations via SUBMIT DE
• Handle timeouts gracefully (see error handling)

Your customer’s responsibility (taxpayer)

• Have an ERS with integrated TSS attached to their account
• Deliver TSS exports and DSFinV-K exports to auditors within required timeframes
• Maintain backups of fiscal data (10-30 years retention, two physical locations recommended)

fiskaly’s responsibility

• Operate and maintain the certified Cloud-TSS (99.9% uptime SLA)
• Provide software updates and security patches (free of charge)
• Handle certification renewals
• Maintain API availability and performance

Compliance checklist for go-live

Before launching in production, verify:

• For each location/shop make sure to have an individual TSS created, set to UNINITIALIZED, Admin PIN set and TSS set to INITIALIZED
• Client created for each POS terminal
• Every transaction is signed (start + finish lifecycle)
• Receipt includes KassenSichV QR code (format reference)
• QR code validates correctly (validation tool)
• DSFINVK DE cash point closings generate successfully
• SUBMIT DE declaration accepted by ELSTER
• Signing timeout is 3-5 seconds and does not block checkout
• Retry logic handles 5xx errors with exponential backoff
• Admin is logged out after provisioning
• LIVE environment provisioned separately from TEST

⚠️A missing signature does not invalidate a receipt

If the TSS is unavailable, issue the receipt with a note like “TSS not available” and include the unsigned transaction in your DSFinV-K export. See error handling for details.

Documentation

Getting started

Introduction

KassenSichV background, Deutsche Fiskal acquisition, certification details

New Customers Guide

Step-by-Step: account setup through first signed transaction with code examples

Technical Details

TSS architecture, transaction data flow, and cryptographic signing process

Guides

Error Handling

Timeout strategy, retry logic, and what to do when the TSS is unavailable

Postman Tutorial

Interactive API exploration — no code required

Dashboard Manual

Manage organizations, API keys, and TSS through the web UI

Compliance

Receipt Data

Mandatory receipt fields and QR code content specification

QR Code Validation

Validate that your QR codes are KassenSichV-compliant

Certification

BSI certification documents and validity periods

Related products

DSFINVK DE

Fiscal data export — required for Germany, references SIGN DE data

SUBMIT DE

ELSTER filing — required for Germany since 2025

SAFE

Long-term archival of fiscal exports (recommended)

Reference

API Reference (SIGN DE v2)

Interactive endpoint documentation with all schemas

Glossary

KassenSichV terms: TSS, ERS, DSFinV-K, and more

Support

How to get help, example collections, and contact channels