The reason for the discrepancy between the calculations in 1C and the online calculator is that the CSMI (contributions for compulsory social medical insurance) was not enabled in the calculation type settings. Because of this, the program did not take this contribution into account when calculating, and the resulting tax amounts did not match the expected ones.
How to fix it
You need to check the calculation type used for accrual and make sure that CSMI is enabled in it. If this parameter is not checked, it must be enabled, after which the accruals should be recalculated. After enabling CSMI, the calculation of taxes and contributions will be performed correctly, and the results in 1C will correspond to the actual regulatory calculations.
It is important to understand that online calculators may use simplified or outdated calculation formulas, so first of all you should check the settings in the program itself — the calculation type, rates, and the components included in it (MPC, CSMI, SF, SI, and other mandatory payments). If one of the components is not included in the calculation type, this will inevitably lead to a distortion of the final amount.
Frequently asked questions
How to check whether CSMI is enabled in the calculation type?
You need to open the settings of the calculation type applied to the employee or accrual, and check the composition of the included contributions and taxes.
Can the absence of CSMI affect other calculations?
Yes, if CSMI is not enabled, this affects the final amount of deductions and accruals, and may also affect contribution reporting.
Is it necessary to recalculate previous periods after the correction?
If the error in the calculation type was in effect for several periods, the accruals for these periods should also be rechecked and recalculated if necessary.