The formula is simple: DTI = (all existing monthly loan payments + the target new instalment) / net monthly income. Example: you net 6 000 PLN. You carry a cash loan at 400 PLN/month, a credit card with 200 PLN minimum payment, a payday loan at 500 PLN/month. You want a mortgage with a 2 200 PLN instalment. DTI = (400 + 200 + 500 + 2 200) / 6 000 = 55%. The bank declines. Same case without the payday and card: DTI = (400 + 2 200) / 6 000 = 43%. Bank approves reluctantly. Without the cash loan: DTI = 2 200 / 6 000 = 37%. Green light.
What counts as „monthly obligation". Every loan and credit line in BIK. Credit cards: the minimum monthly payment (usually 3–5% of balance) plus the card limit × 3–5% as potential load, even on an empty card. Payday and non-bank loans get the harshest treatment. Alimony. Bailiff seizures. Not counted: bills (electricity, internet), rent, family living costs — those sit in a second ratio (income surplus for living).
How to lower DTI. Repay payday loans and credit cards before applying — immediate ratio drop. Close unused limits (even a zero-balance card counts through potential). Prove extra income (second job, dzieło contract registered 6 months+, rental income from a land registry). Consolidation: several 500 PLN payments into one 800 PLN payment drops DTI, but stretches the loan. Does not work: „I will get a raise in three months" — the bank looks at the last 3–6 months, not the future.
Frequently asked questions
In Polish bank practice in 2026: up to 40% green, 40–50% possible, 50%+ declined. KNF's Recommendation S sets 40% max for low-income clients and 50% for high-income.
Yes. The bank assumes you can draw the limit any time, so it counts 3–5% of the limit as potential load. A 20 000 PLN limit card, even empty, loads DTI by 600–1 000 PLN/month.
Depends. Paying — an obligation, in DTI. Receiving — income (if court-ordered and regularly received).