Your employer withholds income tax every month. Over a whole year, the tax can turn out lower: if you worked only part of the year, or can claim your spouse, mortgage interest, pension savings or donations. This gives a rough estimate of the refund. Nothing is sent to us.
How the estimate works
Over the year, your employer withholds tax every month as if you earn the same all year. The yearly tax is calculated on your real income for the year, and the full yearly tax credits apply even if you worked only a few months. That is why people who arrived in, or left, the Czech Republic during the year often get money back.
From your gross salary we deduct mortgage interest (up to 150,000 CZK), pension and life insurance savings (up to 48,000 CZK together) and donations (if they are at least 2% of the tax base or 1,000 CZK, up to 15% of it). Tax is 15%, and 23% above the yearly limit. From the tax come the credits: the taxpayer credit, your spouse, and, from 2027, the student credit. Child credits come last; if they are higher than the tax, you get the rest as a tax bonus.
This is an estimate. It assumes Czech employment income only, children and spouse for the whole year, and that your employer withheld tax with your signed tax declaration. Not included: income from abroad, rent, investments or a trade license, disability credits and the kindergarten credit. With any of those, you file a personal income tax return yourself instead of the employer's yearly settlement (roční zúčtování). For the 2025 tax year, choose 2026: the credits were the same, only the 23% limit was lower (1,676,052 CZK).
Official sources
Income Tax Act 586/1992 Sb. (§ 15, § 16, § 35ba, § 35c, § 38ch); financnisprava.cz.
