How Polish banks calculate borrowing capacity: income, living costs, limits and the rate buffer

Your borrowing capacity (zdolność kredytowa) is the largest loan a bank thinks you can repay safely. Broadly, the bank takes your confirmed net income, subtracts living costs and existing commitments, and checks whether the instalment still fits if interest rates rise by at least 2.5 percentage points. The result is often lower than people expect, and the stress test is usually the reason.

Each bank uses its own model, so two banks can give you quite different figures. This page explains the parts every Polish bank works with, under KNF Recommendation S, and shows a worked example. It is information, not financial advice.

The five building blocks

1. Income the bank will count

Banks must base the assessment on confirmed and stable income of all applicants (and any guarantors). Irregular income, such as bonuses or commission, is counted only after individual assessment, and some banks count only part of it. The bank looks at disposable (net) income.

Typical documents are an employment contract, an employer's income certificate, recent bank statements and the last tax return. Self-employed applicants show business records instead. Exact lists vary by bank.

If you earn in more than one currency, Recommendation S tells banks to assume that every currency other than your main one loses 50% of its value. A salary in złoty plus rental income in euros will therefore count for less than its face value.

2. Living costs

The bank deducts a monthly allowance for living costs, which depends on household size and sometimes region and housing status. Recommendation S does not let banks go below independent household-budget data, and after paying the instalment each member of the household must still be left with at least the social minimum.

Banks do not publish their tables. Published guides in 2026 quote roughly 1,300–1,700 zł a month for the first adult and 700–1,100 zł for each additional person. Our /en/toolbox/borrowing-capacity uses mid-points of these ranges as illustrative defaults; your bank's figure may differ.

3. Existing commitments

Every instalment you already pay is deducted: car loans, consumer loans, leasing, instalment purchases. Banks must check total debt, including loans from non-bank lenders.

Credit limits count even if you never use them. Each bank chooses its own method, and market sources quote a charge of roughly 3–5% of the limit per month. A 10,000 zł card limit you never touch can therefore reduce your monthly budget by 300–500 zł in the bank's eyes.

Watch out: closing unused credit cards and overdraft limits before you apply is one of the few quick ways to raise your capacity. Do it before you apply, not in the middle of the process, because the bank checks your credit-bureau (BIK) record as part of the assessment.

4. The interest-rate buffer

For floating-rate loans the bank does not test your budget at today's rate. It adds a buffer of at least 2.5 percentage points, and in some market conditions more; banks may add extra on top. For loans with a rate fixed for at least five years the buffer is smaller and shrinks the longer the fixed period.

5. Term and debt-to-income ratio

Banks can lend for up to 35 years, but if the term is longer than 25 years they are expected to assess capacity as if it were 25. So stretching the term beyond 25 years lowers your actual instalment but helps the capacity calculation less than you might think.

Recommendation S also asks banks to pay special attention when all your debt instalments exceed 40% of net income (for incomes up to the regional average) or 50% (above it). This is a warning threshold, not a legal limit. Each bank sets its own maximum ratio.

A worked example

All figures are assumptions chosen to show the mechanism, not an offer.

• Household: two adults, no children, joint net income 12,000 zł a month in złoty.
• Living costs used by the bank: 1,500 + 900 = 2,400 zł.
• Existing car loan: 800 zł a month.
• Unused credit-card limit: 10,000 zł, counted at 3% = 300 zł.
• What is left for a mortgage instalment after these: 12,000 − 2,400 − 800 − 300 = 8,500 zł.
• Assume the bank's own policy caps the new instalment at 4,000 zł for this household (for example through its debt-to-income limit).
• Offer rate: 6.0% a year, floating. Term assessed: 25 years.

	Rate used	Instalment per 100,000 zł	Maximum loan at a 4,000 zł instalment
Without buffer	6.0%	about 644 zł	about 621,000 zł
With 2.5 pp buffer	8.5%	about 805 zł	about 497,000 zł

The buffer alone cuts the maximum loan by about a fifth in this example. Add the own contribution (at least 20% of the price, or 10% with extra cover), and the flat this household can afford is roughly 620,000 zł with 20% down, before purchase costs.

How to raise your capacity

These are levers, not promises; each bank weighs them differently.

1. Add a co-borrower. Banks assess all applicants' incomes and costs together.
2. Clear or reduce other debts, and cancel unused card and overdraft limits.
3. Consider a rate fixed for five years or more, which lowers the stress buffer under Recommendation S. Weigh this against the fixed-rate price.
4. Put down more. A larger own contribution reduces the loan you need, and some banks price loans better at lower loan-to-value.
5. Wait for a longer income history, especially after a job change or if you are newly self-employed.
6. Ask several banks. Living-cost tables, the treatment of bonuses and foreign income, and maximum ratios all differ.

Foreign borrowers

The same model applies to foreigners. The differences are practical: whether the bank accepts your residence document, how it treats income in another currency, and whether you have Polish credit history. Read mortgages for foreigners explained and the step-by-step mortgage guide for foreigners.

Do not forget the costs

Capacity covers the loan, not the cash you need on top: down payment, notary and court fees, bank charges and fitting out the flat. See the full costs of buying from a developer. Common questions are collected in mortgage and foreigners: questions and answers.