---
title: "Why Personal Income Tax (PIT) is calculated differently than expected"
country: KZ
lang: en
author: Сапа Т.И. (https://buhgpt.kz/authors/sapa-ti)
date: 2026-09-23
canonical: https://buhgpt.kz/suraqtar/pochemu-ipn-nachislyaetsya-ne-tak-kak-ozhidalos-en
source: BuhGPT
---

# Why Personal Income Tax (PIT) is calculated differently than expected

> **TL;DR:** The reason is that last month personal income tax (PIT) was not accrued, and because of this the system accrued it additionally in the current month — which created the impression of an error. What happens in practice If for some reason PIT was not calculated and accrued when 

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The reason is that last month personal income tax (PIT) was not accrued, and because of this the system accrued it additionally in the current month — which created the impression of an error.

What happens in practice

If for some reason PIT was not calculated and accrued when calculating salary for the previous period, the program does not "lose" this amount — it picks up the under-accrued tax and includes it in the calculation for the current month. This is why in the current period the PIT amount may look inflated or unusual to the accountant — in fact it is the current month's amount plus a "tail" from the past.

What needs to be done

1. Check the payslips and accruals for the previous month — whether PIT was actually accrued there.

2. If it turns out that there was no accrual, this explains the difference in the current period — the additional accrual happened automatically during recalculation.

3. Make sure that the base for calculating PIT (employee income, deductions) is correctly reflected in both periods to rule out further discrepancies.

Frequently asked questions

Why didn't the program itself warn that PIT was not accrued last month?

1C relies on the entered data and posted documents for the period. If the salary accrual for the previous month was posted without PIT (for example, due to an input error or an incomplete calculation), the system simply records what exists, and "pulls in" the difference later.

How can this situation be avoided in the future?

After each payroll calculation, it is worth checking employees' payslips and tax amounts before closing the period, so that the missing accrual can be noticed and corrected right away rather than the following month.

Is it necessary to resubmit reporting for the previous period if PIT was not accrued there?

This depends on the specific situation and on whether reporting for that period has already been submitted. Such questions are better considered individually, comparing the dates of accruals and form submissions.

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