The payment of the contributions provided for in article L. 3421-2 for the financing of the expenses of the Paris fire brigade intervenes under the following conditions:
a) With regard to operating expenses, the departments of Hauts-de-Seine, Seine-Saint-Denis, Val-de-Marne shall pay each year, in respect of the current financial year, advance payments each corresponding to 30% of their forecast contribution as it results from the amount of revenue entered for this purpose in the operating section of the special budget of the police prefecture. These instalments must be paid no later than 15 February, 15 May and 15 August. The balance of the contribution due in respect of the financial year in question is paid in the light of the result of the administrative account;
b) With regard to capital expenditure, excluding that financed by deduction from operating revenue and direct labour, the contribution of the departments concerned to expenditure for the current financial year is paid at the end of each quarter in the light of a summary statement of the mandates issued by the Prefect of Police during that quarter.