OpenFisca

COLLECTIVE

rules as code

digital public good

Open source

Fiscal Host:

The most widely adopted free and open-source engine to write Rules as Code

This is OpenFisca's page OpenFisca

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Become a financial contributor.

Financial Contributions

Membership

Individuals

Get voting rights at the Association in colleges A, D and E. Indexed on mean daily income in country of activity. Please calculate your contributio... Read more

Starts at

€0.50 EUR / year

Latest activity by

+ 26

Membership

Service providers

For legal entities selling OpenFisca implementation or support services (college C). Yearly contribution is 3% of gross revenue from OpenFisca-rela... Read more

Starts at

€50 EUR / year

Latest activity by

Membership

Legal entities users

For legal entities using OpenFisca to deliver services to end users (college B). Contribution is indexed on national GNI per capita. Please calcul... Read more

Starts at

€250 EUR / year

Latest activity by

Custom contribution

Donation

Support the OpenFisca Association with no voting rights, or as an addition to a membership. Thank you! 🙇

Starts at

€1 EUR

Latest activity by

Events

OpenFisca is hosting the following events.

Past event

Community Gathering

Mar 19, 2025

01:30 PM-04:00 PM UTC

Meet fellow OpenFisca users and contributors

Attended by

Past event

Association Launch Event

Mar 19, 2025

08:00 AM-10:30 AM UTC

Be part of the official start of the next stage for the OpenFisca community!

Attended by

Top financial contributors

Individuals

Antoine Bozio

€4,000 EUR since Jan 2025

Salsa Digital

€3,306 EUR since Jan 2025

ESTHER

€295 EUR since Mar 2025

Johan Richer

€50 EUR since Mar 2025

Emmanuel Raviart

€45 EUR since Jan 2025

Mahdi Ben Jelloul

€45 EUR since Jan 2025

Hamish Fraser

€45 EUR since Jan 2025

Nadia Webster

€45 EUR since Jan 2025

Taka

€45 EUR since Jan 2025

Maxime BOLLENGIER

€45 EUR since Jan 2025

Sandra Chakroun

€45 EUR since Jan 2025

maukoquiroga

€45 EUR since Jan 2025

Maxime

€45 EUR since Mar 2025

Serge bossini

€45 EUR since Mar 2025

Philippe

€45 EUR since Mar 2025

Organizations

The Tides Foundation

€4,593.73 EUR since Apr 2024

Codeur·euses en Liberté

€1,000 EUR since Jan 2025

Assemblic

€1,000 EUR since Mar 2025

Verb

€550 EUR since Jan 2025

OpenFisca is all of us

Our contributors 39

Thank you for supporting OpenFisca.

Salsa Digital

Admin

€3,306 EUR

Mahdi Ben Jel...

Admin

€45 EUR

OpenFisca since 2011

Matti Schneider

Admin

Lola Josseran...

Admin

Support

Core Contributor

The Tides Fou...

€4,594 EUR

Antoine Bozio

Legal entities users

€4,000 EUR

Codeur·euses ...

Service providers

€1,000 EUR

Assemblic

Service providers

€1,000 EUR

Verb

Service providers

€550 EUR

ESTHER

Individuals

€295 EUR

Johan Richer

Individuals

€50 EUR

Budget

Transparent and open finances.

Expenses

All time

Expenses paid

Amount disbursed

€239.82

Tags	# of Expenses	Amount
no tag	1	€239.82

View all paid expenses →

Contributions

All time

Contributions received

Amount collected

€15,790.60

Tiers	# of Contributions	Amount
one-time	5	€10,149.73
recurring	32	€5,640.87

View all contributions →

About

The most widely adopted free and open-source engine to write rules as code

Government departments, lawmakers and civil society finally share a common language to debate and activate social and fiscal policies: OpenFisca enables collaboratively modelling laws and regulations and making them computable over open APIs for developers, datascientists and researchers.

Policy experts and governments

OpenFisca enables institutions to efficiently share regulation updates and to pool IT costs. Interconnecting rules across public bodies in the form of legible parameters and executable code provides algorithmic transparency and reduces the bill for the taxpayer.

Developers and datascientists

OpenFisca enables developers to easily deliver apps calculating complex taxes and benefits through its JSON web API, and datascientists to compute large-scale through its vectorial Python API. Contributing formulas and coding extensions enables building services for any business.

Economists and researchers

OpenFisca enables economists and researchers to use survey and administrative data to simulate the impact of any past or future reform on the income distribution of a given population. Linking all computed taxes and benefits enables analysing how multiple reforms interact.

International recognition

OpenFisca is recommended by the OECD to enable “better policy outcomes and enhanced service delivery”.
Received the Edge of Government Innovation Award 2023 at the World Government Summit
Received the Most Innovative Open-Source Software Award 2019 by the European Commission
Recognised as a Digital Public Good by the United Nations Development Programme (UNDP), UNICEF and Norad.

Learn all about OpenFisca on openfisca.org!