English to Spanish Bus/Financial Accounting Revenue

[E-mail] Subject: No revenue provisions

Dear XX,

What you are proposing is contrary to the accounting principles applicable in a Corporation such as YYY, where "cash-accounting is not admisible, but rather the accruals principle is applied and the principle of correlation of income and expenditure. In view of the type of services and the way we bill clients under the existing contracts, in some cases we need to recognise revenue before invoicing it (PROVISIONS) or in others not recognise revenue invoiced (deferrals)