This guide is for an individual letting a flat that is not part of business assets. That income falls under § 9 of the Income Tax Act (Act No. 586/1992 Sb.). A company pays corporate income tax, and rent from an asset held in a trade is taxed as self-employment under § 7. Short stays where you also provide guest services, such as cleaning the room and changing linen, are usually § 7 as well. The platform the guest booked on does not decide that.
What counts as rental income#
The income is the rent you received in the calendar year. Advances for heat, water, and the other services in the service-charge settlement are not extra profit: leave them out of income and out of expenses when you settle them against the real cost. Putting the advances into income without the matching cost taxes money that was only passing through.
A security deposit is not income when the tenant pays it, and returning it is not an expense. Interest on the deposit is a separate calculation.
One method for the whole year#
Expenses are either a lump sum, or the costs you can prove. The choice covers all of your § 9 income in that year: one flat cannot use the lump sum while another uses real costs. You cannot change the method after the fact for a year already chosen. Switching in a later year can require an adjustment of the tax base under § 23(8).
The 30% lump sum#
If you do not claim proven costs, you may deduct 30% of the rental income, and no more than CZK 600,000 a year (§ 9(4)). The cap is reached at CZK 2,000,000 of income. Above that, the deduction stays CZK 600,000. The lump sum already includes every cost of the letting, so depreciation, mortgage interest, repairs, and insurance cannot be added on top. You still keep a record of the income and of receivables connected with the lease.
| Rule | Amount |
|---|---|
| Rate | 30% of rental income |
| Yearly cap | CZK 600,000 |
| Income at which the cap is reached | CZK 2,000,000 |
Real costs#
The other path is costs spent to earn, secure, and keep the rent, which you can show. Only the share that belongs to the letting is deductible when you also use the flat yourself.
- Tax depreciation of the building. Land is not depreciated. The yearly amount is in the depreciation calculator.
- Repairs and maintenance, such as painting or a boiler repair. A technical improvement raises the entry price and is depreciated, rather than deducted in full when you pay it.
- Interest on a loan that financed the rented property. Repayments of the principal are not a cost.
- Property tax, building insurance, management of the property, and the fee for finding the tenant.
Depreciation is the landlord's tax expense. It is not a line in the service-charge settlement and it is not added to the tenant's advances.
The same flat, both ways#
Rent of CZK 20,000 a month is CZK 240,000 a year. Service advances are left out. The lump sum is 30%, so CZK 72,000, and the rental tax base is CZK 168,000.
Real costs on a building with an entry price of CZK 3,000,000 in group 5, straight-line, from the second year: depreciation of CZK 102,000, loan interest of CZK 70,000, and insurance plus property tax of CZK 8,000. That is CZK 180,000 of costs and a rental tax base of CZK 60,000. Here the real costs win. They stop winning once proven costs fall below the CZK 72,000 lump sum, which is the usual case once the loan is gone and the building is already written off.
| 30% lump sum | Real costs | |
|---|---|---|
| Expenses | CZK 72,000 | CZK 180,000 |
| Rental tax base | CZK 168,000 | CZK 60,000 |
| Tax at 15% | CZK 25,200 | CZK 9,000 |
The basic credit for 2026 is CZK 30,840. On its own it covers the tax on a base up to CZK 205,600, so both columns of this example can come out at zero when the rent is your only income. Next to a salary the credit is already used, and the lower rental base is what reduces the tax. The 23% rate applies to the part of the combined tax base above 36 times the average wage, which for 2026 is CZK 1,762,812, not to the rental base by itself. Rental income under § 9 does not attract social security or public health contributions. If you have no other health-insurance title, you can still be a person without taxable income and pay health insurance on that footing.
When the return is due#
File a return when your taxable income for the year is over CZK 50,000, when you show a loss, and, if you are an employee who otherwise meets the conditions, when income under §§ 7 to 10 together is over CZK 20,000. The test uses the rent, not the profit. Rental income goes in annex 2 of the personal income-tax return. With the lump sum you keep income records and a list of receivables. With real costs you keep income and expenses in order, a register of the depreciable building, and, in the year the lease ends, receivables and debts.
| How you file | Deadline |
|---|---|
| Paper return | 3 months after the year ends (1 April) |
| Electronic return | 4 months (1 May) |
| Through a tax adviser | 6 months (1 July) |
If the day falls on a weekend or a holiday, the deadline moves to the next working day. For rent received in 2026 the basic deadline is 1 April 2027. A data box by itself does not move the date.
Common questions
Can I deduct 30% of the rent and depreciation as well?
No. The 30% lump sum, capped at CZK 600,000 a year, already includes every cost of the letting. Depreciation, loan interest, and repairs are available only if you claim real costs instead.
Do service advances count as taxable rent?
Not when you settle them against the real cost of the services. Leave the advances out of income and out of expenses. Taxing the advances without the matching cost taxes money that only passed through.
Is social security due on rental income?
No. Income under § 9 does not create social-security or public-health contributions. If letting is your only activity and nobody else pays health insurance for you, you may still owe health insurance as a person without taxable income.
Income and costs for the property
The return is easier when rent and running costs are already split by property. 2doors keeps that record and exports it at year-end.
See financial reportingA practical guide, not tax advice. The rates and the cap are from Act No. 586/1992 Sb., the Income Tax Act, § 9, as in force for the 2026 tax year. Before you file, confirm which method you are entitled to use and whether a change of method needs an adjustment.