chqr

Swiss QR-bill generation library for Python

Overview

The Swiss QR-bill is the standardized payment slip used throughout Switzerland and Liechtenstein. It combines a machine-readable Swiss QR Code with human-readable payment information, making it easy for individuals and businesses to process payments efficiently.

chqr is a Python library that generates compliant Swiss QR-bills in SVG format. It handles all the complexity of the Swiss QR-bill specification v2.3, including data validation, QR code generation, and proper formatting. The library ensures your generated bills meet the official standards valid from November 21, 2025.

Key Features

• Full compliance with Swiss QR-bill specification v2.3 (November 2025)
• Complete validation of all input data (IBANs, references, amounts, addresses)
• SVG generation with multilingual support (English, German, French, Italian)
• Support for all reference types: QRR (QR Reference), SCOR (Creditor Reference), and NON (no reference)
• Type-safe API with comprehensive error messages
• Zero configuration - works out of the box with sensible defaults

Installation

Install chqr from PyPI using pip:

pip install chqr

Or using uv:

uv add chqr

Quick Start

Here's a minimal example to generate your first Swiss QR-bill:

from decimal import Decimal
from chqr import QRBill, Creditor

# Define the creditor (who receives the payment)
creditor = Creditor(
    name="Max Muster & Söhne",
    street="Musterstrasse",
    building_number="123",
    postal_code="8000",
    city="Seldwyla",
    country="CH",
)

# Create the QR-bill
bill = QRBill(
    account="CH4431999123000889012",  # QR-IBAN
    creditor=creditor,
    amount=Decimal("1949.75"),
    currency="CHF",
    reference_type="QRR",
    reference="210000000003139471430009017",
)

# Generate SVG
svg_content = bill.generate_svg(language="en")

# Save to file
with open("qr_bill.svg", "w", encoding="utf-8") as f:
    f.write(svg_content)

This generates a complete Swiss QR-bill as an SVG file, ready to be printed or included in invoices.

Usage Examples

Basic QR-bill with Debtor Information

Including debtor (payer) information pre-fills the payment slip for your customers:

from decimal import Decimal
from chqr import QRBill, Creditor, UltimateDebtor

creditor = Creditor(
    name="Furniture AG",
    street="Industriestrasse",
    building_number="45",
    postal_code="3007",
    city="Bern",
    country="CH",
)

debtor = UltimateDebtor(
    name="Anna Müller",
    street="Hauptstrasse",
    building_number="12",
    postal_code="8001",
    city="Zürich",
    country="CH",
)

bill = QRBill(
    account="CH5800791123000889012",
    creditor=creditor,
    debtor=debtor,
    amount=Decimal("550.00"),
    currency="CHF",
    reference_type="SCOR",
    reference="RF18539007547034",
    additional_information="Invoice #2024-0156",
)

svg = bill.generate_svg(language="de")

Different Reference Types

The library supports all three reference types defined in the Swiss QR-bill standard.

QRR: QR Reference

QR References are 27-digit numeric references that can only be used with QR-IBANs (IBANs with IID in range 30000-31999):

bill = QRBill(
    account="CH4431999123000889012",  # QR-IBAN (IID: 31999)
    creditor=creditor,
    amount=Decimal("250.00"),
    currency="CHF",
    reference_type="QRR",
    reference="210000000003139471430009017",  # 27 digits with check digit
)

SCOR: Creditor Reference (ISO 11649)

Creditor References are alphanumeric references that must be used with regular IBANs:

bill = QRBill(
    account="CH5800791123000889012",  # Regular IBAN
    creditor=creditor,
    amount=Decimal("180.50"),
    currency="CHF",
    reference_type="SCOR",
    reference="RF720191230100405JSH0438",  # ISO 11649 format
)

NON: No Reference

When no structured reference is needed, use the NON type with regular IBANs:

bill = QRBill(
    account="CH5800791123000889012",  # Regular IBAN
    creditor=creditor,
    amount=Decimal("75.00"),
    currency="EUR",
    reference_type="NON",
    additional_information="Donation - Thank you!",
)

Optional Features

Additional Information and Billing Data

You can include unstructured messages and structured billing information:

bill = QRBill(
    account="CH5800791123000889012",
    creditor=creditor,
    amount=Decimal("1200.00"),
    currency="CHF",
    reference_type="SCOR",
    reference="RF18539007547034",
    additional_information="Order #2024-0891 from 15.10.2024",
    billing_information="//S1/10/10201409/11/201021/30/102673386",
)

Alternative Payment Procedures

Support for alternative payment methods like eBill:

bill = QRBill(
    account="CH5800791123000889012",
    creditor=creditor,
    amount=Decimal("450.00"),
    currency="CHF",
    reference_type="SCOR",
    reference="RF18539007547034",
    alternative_procedures=["eBill/B/customer@example.com"],
)

Multilingual Support

Generate QR-bills in any of the four official Swiss languages:

# German
svg_de = bill.generate_svg(language="de")

# French
svg_fr = bill.generate_svg(language="fr")

# Italian
svg_it = bill.generate_svg(language="it")

# English (default)
svg_en = bill.generate_svg(language="en")

Notification Payment

You can generate QR-bills with a zero amount for notification purposes (e.g., eBill enrollment). This automatically adds the required "DO NOT USE FOR PAYMENT" text (or its translation) to the bill.

bill = QRBill(
    account="CH5800791123000889012",
    creditor=creditor,
    amount=Decimal("0.00"),  # Triggers notification mode
    currency="CHF",
    # "DO NOT USE FOR PAYMENT" is automatically added to additional_information
)

API Reference

QRBill

The main class for creating Swiss QR-bills.

QRBill(
    account: str,
    creditor: Creditor,
    currency: str,
    amount: Decimal | None = None,
    reference_type: str = "NON",
    reference: str | None = None,
    additional_information: str | None = None,
    debtor: UltimateDebtor | None = None,
    billing_information: str | None = None,
    alternative_procedures: list[str] | None = None,
)

Parameters:

• account (str): IBAN or QR-IBAN, exactly 21 characters. Must be from Switzerland (CH) or Liechtenstein (LI).
• creditor (Creditor): Creditor information (who receives the payment).
• currency (str): Payment currency, either "CHF" or "EUR".
• amount (Decimal | None): Payment amount with exactly 2 decimal places. Range: 0.01 to 999,999,999.99 (or 0.00 for notification). Can be None for open amounts.
• reference_type (str): Reference type - "QRR", "SCOR", or "NON". Default: "NON".
• reference (str | None): Payment reference. Required for QRR and SCOR types.
• additional_information (str | None): Unstructured message, max 140 characters.
• debtor (UltimateDebtor | None): Ultimate debtor (payer) information.
• billing_information (str | None): Structured billing information, max 140 characters.
• alternative_procedures (list[str] | None): Alternative payment methods, max 2 items of 100 characters each.

Methods:

• generate_svg(language: str = "en") → str: Generate SVG representation. Language can be "en", "de", "fr", or "it".
• generate_qr_code() → segno.QRCode: Generate the QR code object.
• build_data_string() → str: Build the raw QR code data string.

Creditor

Represents the creditor (invoice issuer) information.

Creditor(
    name: str,
    postal_code: str,
    city: str,
    country: str,
    street: str | None = None,
    building_number: str | None = None,
)

Parameters:

• name (str): Creditor name or company, max 70 characters.
• postal_code (str): Postal code, max 16 characters, without country prefix.
• city (str): City/town name, max 35 characters.
• country (str): Two-character ISO 3166-1 country code (e.g., "CH").
• street (str | None): Street name or P.O. Box, max 70 characters.
• building_number (str | None): Building number, max 16 characters.

UltimateDebtor

Represents the ultimate debtor (payer) information. Has identical parameters to Creditor.

UltimateDebtor(
    name: str,
    postal_code: str,
    city: str,
    country: str,
    street: str | None = None,
    building_number: str | None = None,
)

ValidationError

Exception raised when input data fails validation. All validation happens during QRBill initialization, providing immediate feedback with clear error messages.

from chqr import ValidationError

try:
    bill = QRBill(...)
except ValidationError as e:
    print(f"Validation failed: {e}")

Reference Types Explained

Understanding when to use each reference type is crucial for generating valid QR-bills.

QRR (QR Reference)

The QR Reference is a 27-digit numeric reference with a built-in check digit. It can only be used with QR-IBANs, which are special IBANs with an Institution Identifier (IID) in the range 30000-31999.

When to use: You have a QR-IBAN from your bank and need systematic payment reconciliation with a unique numeric reference.

Format: Exactly 27 numeric digits, where the last digit is a Modulo 10 recursive check digit.

Example: 210000000003139471430009017

SCOR (Creditor Reference)

The Creditor Reference follows the ISO 11649 standard and is an alphanumeric reference. It must be used with regular IBANs (not QR-IBANs).

When to use: You have a regular IBAN and want to use a structured reference for payment reconciliation.

Format: Starts with "RF" followed by 2 check digits and 1-21 alphanumeric characters.

Example: RF720191230100405JSH0438

NON (No Reference)

No structured reference is used. This must be used with regular IBANs (not QR-IBANs).

When to use: No specific payment reference is needed, such as for donations or simple payments where additional information is sufficient.

Format: The reference field remains empty, but you can use additional_information for unstructured messages.

Development

Setup

This project uses uv for dependency management:

# Clone the repository
git clone https://github.com/balsigergil/chqr.git
cd chqr

# Install dependencies
uv sync

# Install pre-commit hooks
uv run pre-commit install

Running Tests

The project follows Test-Driven Development (TDD) practices with comprehensive test coverage:

# Run all tests
uv run pytest

# Run with coverage report
uv run pytest --cov=chqr

# Run specific test file
uv run pytest tests/test_qr_bill.py

# Verbose output
uv run pytest -v

Code Quality

Code formatting and linting is handled by Ruff:

# Format code
uv run ruff format

# Check code
uv run ruff check

# Auto-fix issues
uv run ruff check --fix

Pre-commit hooks automatically run these checks before each commit.

License

This project is licensed under the ISC License. See the LICENSE file for details.

Links & Resources

• PyPI Package: https://pypi.org/project/chqr/
• Swiss QR-bill Specification: SIX Payment Standards
• Official Implementation Guidelines: See assets/ig-qr-bill-v2.3-en.pdf

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Made with ❤️ by Gil Balsiger in Switzerland