Buy-to-Let Flat on a Mortgage – Does It Pay Off at 2026 Interest Rates?

Does a buy-to-let flat on a mortgage pay off? At current rates – the NBP reference rate of 3,75% and average interest on new housing loans of about 6% – the rent from a typical new flat with a 20% down payment does not cover the instalment and costs: in our calculations you top up about 890–1 130 PLN every month. Below we show the calculation step by step at the median prices from our offer in Wroclaw and Warsaw, interest-rate scenarios of ±1 percentage point and the conditions under which leverage starts to work in your favour.

Key facts

• The NBP reference rate is 3,75% (since 5 March 2026), and the average interest on new zloty housing loans in July 2026 was 6,07% (NBP).
• The average rental rate according to the NBP (first quarter of 2026): 85,1 PLN/m² in Warsaw and 67,5 PLN/m² in the group of 6 large cities that includes Wroclaw – excluding service charges.
• With a loan of 80% of the price (30 years, 6,07%), the median 2-room flat from our offer gives a monthly cash flow of about –890 PLN in Warsaw and –960 PLN in Wroclaw.
• Leverage helps only when the net profit from rent (in our case about 3,5–4% of the amount committed) is higher than the loan interest. Today it is the other way round – you can earn mainly on the rise in the flat's value and the capital repaid.
• A loan for a buy-to-let flat is subject to the same rules as an ordinary mortgage: max. LTV 80% (90% with additional security) and an affordability assessment with an interest-rate buffer (Recommendation S).

A mortgage for a second flat – what do banks require?

When you buy a flat to let as an individual (outside a business), you usually take a standard mortgage. The Polish Financial Supervision Authority's (KNF) Recommendation S expressly counts as residential property a unit that is or will be intended for letting by the owner (outside a business). So the same rules apply to you as when buying "for yourself":

• Down payment for an investment flat – LTV when the loan is drawn should not exceed 80%, and 90% only if the part above 80% is additionally secured (for example by low-down-payment insurance). We describe the details and ways of raising funds in the article on the down payment.
• Interest-rate buffer – with a variable rate the bank assesses affordability as if the interest were higher by at least max(5 percentage points – the central bank rate; 2,5 percentage points). With a reference rate of 3,75% the buffer is therefore 2,5 percentage points.
• Debt-service-to-income (DStI) – special caution when 40% of income is exceeded (for incomes up to the regional average) or 50% (for higher ones). If you are already repaying a loan on your own home, its instalment immediately eats part of this limit.
• Term – a loan can run for 30 years, but affordability for a term longer than 25 years is calculated as for 25 years.

How to calculate how much credit you will get on your earnings, we show in the guide to borrowing capacity.

Will the bank count rental income?

Recommendation S requires the bank to rely on confirmed information and to take into account income that is stable throughout the repayment period. It does not exclude rental income, but each bank decides itself whether and to what extent to accept it. Income from a flat you have already been letting for some time (agreement, deposits to the account, PIT-28 return) is much easier to demonstrate than rent from a unit you are only just buying. It is therefore safer to assume that affordability must come from your current income.

Will rent pay the mortgage instalment? A calculation on flats from our offer

We took the median prices from TM Invest offer data as at 27.09.2026: a studio and a 2-room flat in Wroclaw and 2 rooms in Warsaw. Rent is the NBP rate multiplied by the floor area. Assumptions:

• down payment 20%, loan 80% of the price in zlotys, equal instalments, interest 6,07% (NBP average for new housing loans, July 2026);
• occupancy 95% (about 18 days of vacancy a year – the NBP assumes the same);
• flat tax 8,5% of revenue – with private letting you cannot deduct interest or other costs (more: tax on flat rental);
• owner's costs 150 PLN/month (insurance, property tax, minor repairs) – the service charge and utilities are paid by the tenant on top of the rent;
• cash at the start: 20% down payment + about 1% of the price for the notary, court and bank (see costs of buying from a developer) + finishing at 2 000 PLN/m² and 12–15 thousand PLN for furniture and appliances (indicative, cf. finishing cost).

Item	Wroclaw, studio	Wroclaw, 2 rooms	Warsaw, 2 rooms
Price (median in the offer)	595 638 PLN	662 405 PLN	755 824 PLN
Floor area (median)	32,4 m²	40,8 m²	39,4 m²
Rent (NBP rate × m²)	2 187 PLN	2 754 PLN	3 353 PLN
Rent after vacancies (95%)	2 078 PLN	2 616 PLN	3 185 PLN
Flat tax 8,5%	–177 PLN	–222 PLN	–271 PLN
Owner's costs	–150 PLN	–150 PLN	–150 PLN
Rental income before the instalment	1 751 PLN	2 244 PLN	2 765 PLN
Loan (80% of the price)	476 510 PLN	529 924 PLN	604 659 PLN
Instalment – 30 years, 6,07%	2 878 PLN	3 201 PLN	3 652 PLN
Monthly cash flow	–1 127 PLN	–957 PLN	–888 PLN
Cash committed at the start	about 202 thousand PLN	about 236 thousand PLN	about 253 thousand PLN
Cash-on-cash (annual cash flow / cash)	–6,7%	–4,9%	–4,2%
Capital repaid in the 1st year	5 776 PLN	6 423 PLN	7 329 PLN

Example for Wroclaw: 2 rooms for 662 405 PLN – the median in our offer – at a rate of 67,5 PLN/m² give 2 754 PLN of rent. After vacancies, tax and costs 2 244 PLN remains, while the instalment on a loan of 529 924 PLN over 30 years is 3 201 PLN. You are short 957 PLN a month, that is about 11,5 thousand PLN a year, which you top up out of your own pocket. Part of that amount is not "lost", however: in the first year you repay 6,4 thousand PLN of capital, which increases your share in the flat.

With a 25-year loan the instalment rises to 3 437 PLN (Wroclaw) and 3 922 PLN (Warsaw), and the monthly shortfall to about 1 160–1 190 PLN. The studio comes out worst: rent calculated at the average rate per m² rises more slowly than the price, although in practice small units can let for more per metre. You will find a comparison of the two floor areas in the article studio or 2 rooms to let.

Want to check how much credit you will get for a second flat and what your instalment would look like with a fixed and a variable rate? Book a consultation with a mortgage expert – we will compare offers from several banks and calculate whether the rent can carry the instalment in your case.

What changes when rates fall or rise by 1 percentage point?

The loan interest is the biggest variable in this calculation. Below is the same 30-year loan at interest lower and higher by 1 percentage point than the current average.

Loan interest	Wroclaw 2 rooms – instalment	Wroclaw – cash flow / cash-on-cash	Warsaw 2 rooms – instalment	Warsaw – cash flow / cash-on-cash
5,07% (–1 percentage point)	2 867 PLN	–624 PLN / –3,2%	3 272 PLN	–507 PLN / –2,4%
6,07% (NBP average, VII 2026)	3 201 PLN	–957 PLN / –4,9%	3 652 PLN	–888 PLN / –4,2%
7,07% (+1 percentage point)	3 551 PLN	–1 307 PLN / –6,7%	4 051 PLN	–1 287 PLN / –6,1%

Even a fall in interest of a whole point does not turn the calculation positive. For rent at LTV 80% to cover the instalment, interest would have to fall to about 3,0% in Wroclaw and about 3,65% in Warsaw – or the rent would have to rise to about 3 860 PLN (about 94 PLN/m²) in Wroclaw and 4 370 PLN (about 111 PLN/m²) in Warsaw. Since 2022 most new housing loans have been loans with a periodically fixed rate (about 64% in the first quarter of 2026 according to AMRON data cited by the NBP) – a fixed rate does not improve the result, but protects against the "+1 percentage point" scenario for the first years.

20% or 50% down payment? When leverage helps and when it hurts

The rule is simple: a loan raises your return only when the flat "earns" more than the borrowed money costs. In our examples net rental income is about 3,5–4% of the whole amount committed a year, while the loan costs about 6%. Every borrowed zloty therefore lowers the current return. You can see this by comparing three financing options:

2-room flat	LTV 80% (20% down payment)	LTV 50% (50% down payment)	For cash
Wroclaw Fabryczna – 511 792 PLN, 37,4 m²	–429 PLN / –2,6%	+499 PLN / +1,7%	+2 044 PLN / +4,0%
Wroclaw – 662 405 PLN, 40,8 m²	–957 PLN / –4,9%	+243 PLN / +0,7%	+2 244 PLN / +3,5%
Warsaw – 755 824 PLN, 39,4 m²	–888 PLN / –4,2%	+482 PLN / +1,2%	+2 765 PLN / +3,9%

Cheaper flats come out better: the median for 2 rooms in Wroclaw's Fabryczna district is 511 792 PLN and there, with a 20% down payment, the shortfall falls to about 430 PLN a month. You will find a full overview of returns for different locations in the article on rental yield.

Where, then, does a loan make sense? In three situations:

• Growth in the flat's value. Leverage works on the whole price, not only on the down payment. Every 1% rise in the value of a flat worth 662 thousand PLN is about 6,6 thousand PLN, that is about 2,8% relative to the 236 thousand PLN of cash committed. There is, however, no guarantee of growth – prices may also stand still or fall.
• Repayment of capital by the tenant. The rent covers most of the instalment, so each year your share in the flat grows faster than the top-up payments alone would suggest.
• A fall in rates or a rise in rents in the long term. The instalment (with a fixed loan amount) does not rise with inflation, while rents can rise along with it. After a few years the calculation may turn around – provided you can endure the period of top-ups.

For comparison with other ways of placing money – the NBP estimates that letting a flat bought for cash gave in the first quarter of 2026 a return slightly higher than deposits, but lower than 10-year treasury bonds. You will find a detailed comparison in the text flat or bonds.

Why are our results worse than the "6% yield" from the reports?

The NBP states that in the first quarter of 2026 the capitalisation rate (annual rent to price) was 5,95% in Warsaw and 6,24% in six large cities. We get a gross 5,0% in Wroclaw and 5,3% in Warsaw. The difference comes from the price: the NBP calculates the average transaction price from the primary and secondary markets (in Warsaw 17 159 PLN/m²), while new 2-room flats in our offer cost a median of 18 600 PLN/m² in Warsaw and 16 000 PLN/m² in Wroclaw – and finishing comes on top. A new flat does, however, give lower renovation costs in the first years and easier letting.

Conclusion: before you compare the "yield" from a report with the loan interest, calculate it on a specific unit, with tax, vacancies and finishing. We write more about how a flat performs as an investment in the broader view in the guide a flat as an investment.

How to improve the calculation for a buy-to-let flat on a mortgage?

• Look for a lower price per m² – in our offer the median for the whole of Wroclaw is 15 736 PLN/m², in Fabryczna 13 394 PLN/m², and in Warsaw in Białołęka 14 122 PLN/m² against 18 000 PLN/m² for the whole city. Browse developments in Wroclaw and in Warsaw.
• Increase the down payment – with a down payment of about 50% the cash flow is positive in all our examples.
• Extend the loan term – 30 instead of 25 years lowers the instalment by about 235–270 PLN, although it increases the total cost of interest.
• Do not overpay for finishing – a "for letting" standard is cheaper than "for yourself", and every 10 thousand PLN less means a higher return on cash.
• Keep a financial cushion – at least for several months of instalments without a tenant and for a rise in interest.

Frequently asked questions

Summary

A buy-to-let flat on a mortgage at current rates rarely pays for itself. With a 20% down payment and interest of about 6%, the rent from a typical new flat in Warsaw and Wroclaw covers about 70–76% of the instalment. You top up the rest, counting on repayment of capital and growth in rents and in the value of the unit. Leverage starts to help only with a lower price per m², a higher down payment or clearly lower rates. So before buying, calculate it on a specific flat and check whether you can carry the top-ups for several years.

Looking for a flat to let? We will help you choose and buy a flat from a developer – in most cases with no commission for you, because the developer usually pays our fee. If you need financing, our mortgage expert will compare offers from several banks. TM Invest has been on the market since 2016.

Legal position as at September 2026. The calculations are indicative and based on the assumptions described in the text (NBP rental rates, median prices from the TM Invest offer as at 27.09.2026, NBP average interest). The article is not an investment recommendation or tax advice; loan terms depend on the bank and your situation.

Sources

• NBP – basic interest rates (reference rate 3,75% since 5.03.2026)
• NBP – MIR interest-rate statistics, table 4: average interest on new agreements in PLN (July 2026)
• NBP – Information on housing prices and the situation on the residential and commercial real estate market in Poland in the first quarter of 2026 (rental rates, capitalisation rate, chapter 7)
• KNF – Recommendation S (definitions 7a and 21, rec. 7, 8, 9.3, 15.5)
• Act on the Flat-Rate Income Tax, consolidated text Dz.U. 2025 item 843 – Art. 12(1)(4)(a)
• podatki.gov.pl – settlement of rental income (recorded flat-rate tax)
• Flat prices: TM Invest development catalogue, as at 27.09.2026