Article R3421-1 of the French General Code of Local Authorities
The revenue and expenditure of shared services of local interest, entered in the budget of the city of Paris (special budget of the police prefecture), are subject, to a contribution from the départements of Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne, under the conditions set out in articles R. 2512-27, R. 2512-28 and R. 2512-29.