A fundamental concept of basic accounting. In any one given accounting period, you should try to match the revenue you are reporting with the expenses it took to generate that revenue in the same time period, or over the periods in which you will be receiving benefits from that expenditure. A simple example is depreciation expense. If you buy a building that will last for many years, you don't write off the cost of that building all at once. Instead, you take depreciation deductions over the building's estimated useful life. Thus, you've "matched" the expense, or cost, of the building with the benefits it produces, over the course of the years it will be in service. A fundamental rule f baxic accounting. In any one given accounting period, you should try to match the revenue you are reporting with the expenses it took.

This definition is in context to Accounting. See more contextual defintions for Matching Principle.