Treasury bonds or a bank deposit — which pays more?

At today's rates, a deposit pays more for a year, and treasury bonds pay more for 3 and 4 years. After 3 years, PLN 10,000 grows after the 19% Belka tax to PLN 10,939 on a 12-month deposit at 3.75% (today's NBP reference rate), renewed every year, and to PLN 11,264 in EDO bonds. To match EDO bonds, a deposit would need at least 5.00% a year — 1.25 percentage points more than the NBP reference rate.

How much do a deposit and bonds earn?

We compare PLN 10,000 put away for 1, 3 and 4 years. On one side is a 12-month bank deposit (lokata) with the interest added at the end of the term, renewed every year together with the interest. Its rate is 3.75% a year — the NBP reference rate (stopa referencyjna) since March 5, 2026. On the other side are three of the Polish treasury savings bonds (obligacje skarbowe) anyone can buy, from the October 2026 offer:

• TOS — 3-year, with a fixed rate of 4.40% for the whole term. Interest is added to the bond every year and paid at the end.
• COI — 4-year. 4.75% in the first year, then inflation plus a 1.50% margin (5.60% at today's inflation). Interest is paid out every year.
• EDO — 10-year. 5.35% in the first year, then inflation plus a 2.00% margin (6.10% today). Interest is added every year and paid at redemption.

All amounts are after podatek Belki, the Belka tax (19% of the interest), which you pay on deposits and bonds alike. Our guide to the Belka tax explains how it works.

For a year, the deposit pays more: PLN 10,304, PLN 29 more than the best bonds — TOS (PLN 10,275). None of these bonds reaches its redemption date within a year, so you redeem them early and pay the early redemption fee: TOS — PLN 1.00, COI — PLN 2.00 and EDO — PLN 3.00 per bond. The fee is taken from the accrued interest, so it cuts the gain. Without the fee, EDO bonds would give PLN 10,433 after a year — more than the deposit, so the fee decides the result.

For 3 years, EDO bonds pay the most: PLN 11,264, PLN 325 more than the deposit (PLN 10,939). After 3 years TOS bonds mature with no fee, while COI and EDO bonds are redeemed early, with the fee.

For 4 years, EDO bonds pay the most: PLN 11,849, PLN 577 more than the deposit (PLN 11,272). After 4 years COI bonds mature with no fee, and EDO bonds are redeemed early. TOS bonds mature after 3 years — the proceeds buy new ones (the same number by exchange at PLN 99.90, more with the rest at PLN 100), and these are redeemed early a year later.

For one or two years, the State Treasury also sells 1-year ROR and 2-year DOR bonds. Their rate is set every month from the NBP reference rate, but our calculator doesn't include them, so they aren't in this comparison.

We assume inflation stays at the latest GUS (Statistics Poland) figure — 4.1% in September 2026 — for the whole time, that the deposit rate doesn't change, and that the bond offer in 3 years' time will be the same as today's. COI interest, paid out every year, counts as cash and isn't reinvested.

What deposit rate would match the bonds?

We look for the lowest rate (to 0.01 percentage points) at which the deposit in this comparison ends with at least as much as the best of TOS, COI and EDO:

• For a year: to match TOS bonds (PLN 10,275), a deposit needs only 3.40% a year — 0.35 percentage points less than the NBP reference rate.
• For 3 years: to match EDO bonds (PLN 11,264), a deposit would need at least 5.00% a year — 1.25 percentage points more than the NBP reference rate.
• For 4 years: to match EDO bonds (PLN 11,849), a deposit would need at least 5.35% a year — 1.60 percentage points more than the NBP reference rate.

These numbers include the Belka tax on both sides and the bonds' early redemption fees. If your deposit adds interest more often, say monthly, a slightly lower rate is enough, because the interest starts earning interest sooner.

You only know a deposit's rate for the current term: after a year the bank renews it at whatever rate it offers then. TOS have a fixed rate for all 3 years, while COI and EDO follow inflation from the second year.

What's left after inflation?

GUS inflation was 4.1% in September 2026 (year on year). The real result shows what you gain or lose each year after tax and after rising prices — assuming inflation stays at that level.

A deposit at 3.75% returns 3.04% a year after tax — less than inflation, so you lose 1.02% a year in real terms. The best real result in this comparison comes from EDO bonds for 4 years: 0.22% a year above inflation. 2 of the 12 cases in the table make a real gain.

Each option reacts differently when inflation changes. A deposit usually has a fixed rate until the end of the term, and on renewal you get whatever the bank offers then. TOS have a fixed rate for 3 years, so if prices start rising faster, they earn less in real terms. From the second year COI and EDO pay inflation plus a margin: when inflation rises, so does their rate. When it falls, their rate falls too, but never below the margin, because negative inflation counts as zero.

The inflation calculator shows how inflation changes the value of money over the years, and our guide "Inflation and your savings" covers how to protect your savings from it.

How else do deposits and bonds differ?

The BFG limit applies to each bank separately, to the total of all your money in that bank, interest included.

When you redeem bonds early you don't have to return them all: you choose how many, and pay the fee only on those. For TOS and EDO the fee can't exceed the accrued interest, so you never lose the money you put in. The rules for breaking a deposit — whether you lose all the interest or part of it — are in its terms and conditions.

Does a promotional deposit change the result?

Banks often advertise deposits with rates well above their standard ones. Before you compare one with bonds, check the conditions. Promotional deposits may be:

• for new money only (money that wasn't in the bank before), or for new customers only;
• short, for example 3 months;
• capped at an amount;
• conditional, for example on opening an account or paying by card.

Deposit rates are quoted per year, and the interest is proportional to the term. A 3-month deposit therefore pays a quarter of the yearly rate, and when it ends the money has to be put somewhere again — often at a lower rate.

To compare such a deposit fairly with bonds, work out a rough average rate over the whole year, for example 3 months of the promotion and 9 months of a standard deposit. Only then compare that average with the rate at which a deposit matches the bonds.

When a deposit, and when bonds?

You don't have to choose between them. Deposits and bonds differ above all in how fast and at what cost you get your money back, so you can split your savings by when you might need them:

• Money for unexpected expenses, your emergency fund — in a savings account or a short deposit. You can get it back quickly, losing at most the current term's interest.
• Money for a purchase in a year or two — on a deposit or in bonds, whichever pays more after fees. The first table in this guide shows the result after a year.
• Money put away for several years — here bonds have an edge over a deposit renewed every year: from the second year COI and EDO protect it against rising inflation, and TOS keep a fixed rate for all 3 years, while a deposit's rate is only known until its next renewal. The tables above show what that's worth at today's rates.

You can buy bonds gradually, say every month. Each batch has the terms of the offer in the month you buy it, and when you need money you redeem only as many bonds as you need. If you're saving for longer than 4 years, compare EDO with COI too — see our guide "EDO or COI?".