Polish treasury bonds calculator

How much will you earn on Polish treasury bonds? Enter an amount and how long you can leave it, and the calculator compares five bonds from the October 2026 offer: 3-year TOS, 4-year COI, 10-year EDO and the family bonds ROS and ROD. You see what you get after the 19% Belka tax and early redemption fees, what that is worth in today's money and which bond comes out ahead over your horizon. Rates are updated automatically every month.

Updated: October 20, 2026 · Offer for October 2026

Amount (PLN)

Each bond costs PLN 100 — you buy as many whole bonds as the amount covers.

For how many years

When you take the money out. Bonds that mature earlier are bought again.

Inflation in the years ahead (%)

Defaults to the latest GUS figure: 4.1% (September 2026). The NBP target is 2.5%. It sets the rate of COI, EDO, ROS and ROD from year 2.

Tax on interest

Interest on bonds is taxed at 19% (Belka tax), withheld automatically at redemption — for COI, at each interest payment. In an IKE retirement account (e.g. IKE-Obligacje) there is no tax if you withdraw after age 60 and meet the statutory conditions.

You earn the most with —

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What you'd get each year

After tax and fees, if you redeemed the bonds that year. The dashed line is the amount grown by inflation — above it you gain in real terms.

TOS COI EDO ROS ROD Amount + inflation

Current treasury bond offer: October 2026

On sale October 1 – 31, 2026. The first year has a fixed rate. From the second, inflation-linked bonds pay inflation plus a margin — the annual GUS figure published in the month before each interest year starts.

Polish treasury bond offer for October 2026
Bond	Term	Year 1	Later years	Interest	Early redemption
TOS1029	3 years	4.40%	fixed 4.40%	added yearly, paid at maturity	PLN 1.00 per bond
COI1030	4 years	4.75%	inflation + 1.50%	paid out yearly	PLN 2.00 per bond
EDO1036	10 years	5.35%	inflation + 2.00%	added yearly, paid at maturity	PLN 3.00 per bond
ROS1032 800+ only	6 years	5.00%	inflation + 2.00%	added yearly, paid at maturity	PLN 2.00 per bond
ROD1038 800+ only	12 years	5.60%	inflation + 2.50%	added yearly, paid at maturity	PLN 3.00 per bond

Latest GUS inflation: 4.1% (September 2026). At that rate, EDO would pay 6.10% in later years and COI 5.60%.

Only recipients of the 800+ child benefit can buy ROS and ROD, up to the total benefit received.

Source: obligacjeskarbowe.pl (run for the Ministry of Finance) and GUS. We fetch the data automatically; last change: October 20, 2026.

Example: PLN 10,000 in bonds for 10 years

You buy bonds for PLN 10,000 from the October 2026 offer and take the money out after 10 years. We assume 4.1% inflation a year and the 19% Belka tax. Bonds that mature earlier are bought again on the same terms.

PLN 10,000 in bonds for 10 years, 4.1% inflation: cash-out value after tax and fees
Bond	You get	Profit	In today's money
ROD 800+ only Redeemed early, after 10 years.	PLN 16,861	PLN 6,861	PLN 11,282
EDO Held to maturity.	PLN 16,440	PLN 6,440	PLN 11,000
ROS 800+ only 1 × 6 years to maturity, then one more series redeemed early, after 4 years.	PLN 15,859	PLN 5,859	PLN 10,611
COI 2 × 4 years to maturity, then one more series redeemed early, after 2 years.	PLN 14,191	PLN 4,191	PLN 9,495
TOS 3 × 3 years to maturity, then one more series redeemed early, after 1 year.	PLN 14,141	PLN 4,141	PLN 9,462

At 4.1% inflation, the best bond anyone can buy is EDO: after 10 years you get PLN 16,440, a profit of PLN 6,440 after tax and fees — PLN 11,000 in today's money. The family bond ROD would give PLN 16,861.

These numbers come from the same calculator you see above, using its default inputs. Enter your own to see your result.

How we calculate

The amount buys whole bonds at PLN 100 each, and the rest stays as cash. Every year a bond earns the offer's rate: fixed in year 1, then — for COI, EDO, ROS and ROD — inflation plus a margin (negative inflation counts as zero). TOS keeps the same rate for all 3 years. TOS, EDO, ROS and ROD add their interest to the bond every year, so it earns interest too. COI pays its interest out every year — we count it as cash, not reinvested.

The 19% Belka tax on bonds that capitalise interest is paid once, at redemption, on all the interest; on COI, at every interest payment. On early redemption the offer's fee is taken from the interest and never exceeds it — except COI from year 2, which charges it in full. Tax is charged on the interest after the fee, rounded to the grosz for each bond, as in the examples on obligacjeskarbowe.pl.

When a bond matures before your horizon, the proceeds buy it again: the same number of bonds at the exchange price (usually PLN 99.90), and more at PLN 100 with the interest. The family bonds ROS and ROD are always bought at PLN 100, as they can't be bought by exchange. New bonds get the current offer's rates. Bonds still running in the final year are redeemed early. Real value is the result divided by (1 + inflation)^years. “Average a year” is the yearly growth rate from the amount to the result after tax and fees.

Assumptions: the offer and inflation stay the same for the whole period (in reality the offer changes every month and inflation every year), redemption always at the end of an interest year, COI interest not reinvested. With IKE we assume a tax-free withdrawal; IKE contribution limits and the 800+ limit for ROS and ROD are ignored.

Frequently Asked Questions

Which Polish treasury bonds should I choose?

It depends on how long you can leave the money and what inflation you expect. TOS have a fixed rate for 3 years and the lowest early redemption fee, so you know the result up front. COI, EDO, ROS and ROD pay inflation plus a margin after the first year, so they protect your savings if inflation rises. EDO and the family bonds add interest to the bond every year, and tax is only paid at redemption. COI suit people who want interest paid out every year, and only recipients of the 800+ child benefit can buy ROS and ROD. Enter your own horizon in the calculator — in the example above, over 10 years, EDO comes out ahead.

How do inflation-linked bonds pay interest?

The first year has a fixed rate known up front — in the October 2026 offer, 5.35% for EDO and 4.75% for COI. From the second year the rate is inflation plus a margin. Inflation is the annual GUS consumer price index published in the month before the interest year starts, and the margin stays the same for the bond's whole term (EDO: 2.00%). Negative inflation counts as zero, so the rate never drops below the margin.

How much does early redemption cost?

The fee depends on the bond. For each PLN 100 bond it is: TOS — PLN 1.00, COI — PLN 2.00, EDO — PLN 3.00, ROS — PLN 2.00, and ROD — PLN 3.00. It is taken from the accrued interest and can't exceed it, so you never lose the money you put in. The exception is COI from the second year, which charges the fee in full. The money arrives 5 working days after you place the order.

Do you pay Belka tax on treasury bonds?

Yes, 19% of the interest. For TOS, EDO, ROS and ROD it is taken once, at redemption, on all the accrued interest — so the future tax keeps earning interest for years. For COI it is taken from each yearly interest payment. You pay no tax if you hold the bonds in an IKE retirement account (e.g. IKE-Obligacje) and withdraw after age 60, meeting the statutory conditions. Choose “0% — IKE” in the calculator to see the difference.

Who can buy the family bonds ROS and ROD?

Only people who receive the 800+ child benefit, up to the benefit they have received — the total paid since it was granted, minus family bonds bought before. In the October 2026 offer the margin is 2.00% for ROS and 2.50% for ROD (compared with 2.00% for EDO and 1.50% for COI). Family bonds can't be bought by exchanging maturing bonds.

Where do the rates come from and how often are they updated?

We fetch the offer automatically from obligacjeskarbowe.pl — the site where the Ministry of Finance sells the bonds — and inflation from GUS (Statistics Poland). We check both every day, so a new offer usually reaches the calculator on the first day of the month. Right now the calculator uses the October 2026 offer (series such as EDO1036) and 4.1% inflation for September 2026.

Guides

EDO or COI? Which Polish treasury bonds to choose

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