Different error budgets are approximated for the First Swiss National Forest Inventory. An error budget displays the effects of individual errors and groups of errors on the accuracy of estimates. The goal of developing the error budgets was to account for the significant sources of errors that can be expected in the national survey. Sources of error included measurement error of quantitative and quantitative attributes, regression error, and sampling error. It was found in general that the national survey system was not very sensitive to unbiased random errors but was sensitive to systematic measurement errors.