Accounting principles state that Revenues and cost must be recorded into the period they belong to; the accounting process which is actionned to do this is called "cut-off"; this is not an OpenErp process as such. a specific cut-off module could be useful (to be developped!; probably using mecanisms similar to the fixed assets depreciation one)

At least such a process is geared on an annual basis for the annual fiscal year. This is why companies make an annual physical inventory of stocks to adjust books with actual physical; they also record assets depreciation and amortization; they also recognize into their books any kind of accruals that were not recorded earlier.

Similarly one may need to apply a proper cut-off for sub-periods (monthly for instance). From an accounting point of view, the accounting entries will be: 1. at the time you receive or create the invoice and book the full amount: debit or credit the partner account and post the counterpart to a balance sheet account (named "deferred costs" or "deferred revenues") 2. at the closing of each period (including the first one) allocate the appropriate amount by debiting or crediting the above account with a counterpart to the Profit and Loss account (sales or expenses)