JMFC calculators
Calculators for accounting, HR and CFO teams
Fast tools for an initial check: tax and ZUS arrears interest, employment cost, cash limits, fiscal register threshold and car cost limits based on CO2 emissions.
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These calculators are informational. For tax decisions, confirm current rules and your specific facts.
Polish tax and ZUS arrears interest calculator
Calculate arrears interest using historical rates from 1999. The result shows a split by year and by rate-change periods.
Principal amount before interest.
ZUS uses the standard tax-interest rate, without reduced or increased modes.
Interest starts on the next day.
The payment day is included.
For ZUS, the calculator applies only the standard arrears interest rate. Reduced and increased rates apply to tax arrears.
How it is calculated: the period is split by rate-change dates. For tax arrears, the reduced mode is applied indicatively from 2009; from 2016 as 50% of the standard rate and earlier as 75%. The increased mode is applied from 2016 as 150% of the standard rate.
interest = arrears amount x days x annual rate / 365
Interest by year
| Year | Start | End | Days | Rate | Interest |
|---|---|---|---|---|---|
| Enter data to see the split. | |||||
The rate table is based on public Ministry of Finance and ZUS data and market summaries for newer changes. The calculator is supportive only; for larger arrears, confirm the amount with the office, e-Tax Office or PUE ZUS.
FAQ: paying tax and ZUS interest
Does the distinction between ZUS and the tax office matter?▾
Yes. ZUS uses the standard arrears interest rate, while reduced and increased rates apply to tax arrears. The transfer title, bank account and balance confirmation route also differ.
How should the transfer to the tax office be described?▾
Use the taxpayer identifier, tax type and period, for example: "NIP 1234567890, VAT-7 04/2026, arrears + interest". For Polish taxes, use the individual tax micro-account and the proper transfer symbol in your banking system.
How should the transfer to ZUS be described?▾
Payments to ZUS should go to the payer's individual contribution account. The title may indicate the period and "contributions + interest", but ZUS booking rules decide how the payment is allocated.
Should I contact the office before payment?▾
For small and clear arrears, a self-calculated payment is often enough. For older periods, corrections, enforcement, instalment arrangements or balance doubts, confirm the amount through e-Tax Office, the relevant office or PUE ZUS.
When can the reduced rate be used?▾
Usually when tax arrears are disclosed in an effective correction and paid within the required deadline. Do not assume the reduced rate automatically during audits, checking activities or after the preference deadline has passed.
Employment cost calculator: employment contract vs B2B
Compare indicative employee net pay, total employer cost and a B2B invoice variant. Assumptions are visible and editable.
Employment contract
Monthly gross salary under employment contract.
PLN 250 or PLN 300 per month where increased commuting costs apply.
Typically PLN 300 per month if the employee filed PIT-2.
Default 1.67%. Your company rate may differ.
B2B / invoice
Net amount before VAT. VAT is usually neutral between active VAT taxpayers.
Costs reduce taxable income under scale and flat tax. For lump-sum tax, they are shown only as cash flow.
Simplified monthly simulation, without annual settlement.
For example 8.5%, 12%, 15% or 17%, depending on the service.
Enter the real amount: full ZUS, preferential ZUS or relief.
Depends on the taxation method and base. Enter the monthly amount.
Employment net0 PLN
B2B cash net0 PLN
B2B vs employment difference0 PLN
Employee social contributions0 PLN
Employee health contribution0 PLN
Employment PIT advance0 PLN
Employer social contributions0 PLN
B2B tax0 PLN
B2B ZUS + health0 PLN
Assumption: the calculator does not include PPK, the 30x social security cap, special reliefs, creative-work costs, the second PIT threshold, health-contribution deductions under flat tax/lump sum, or annual settlement. B2B is a cash-flow simulation, not a tax-form recommendation.
FAQ: employment, B2B and cost of work
Why is employer cost higher than gross salary?▾
The employer finances additional social contributions: pension, disability, accident insurance, Labour Fund and FGSP. Gross salary is therefore not the full employment cost.
Which regulations sit behind social contributions and PIT?▾
The key references include the Polish Social Insurance System Act, the Act on Health Care Services Financed from Public Funds and the PIT Act. Employee tax costs come from art. 22 of the PIT Act, the tax scale from art. 27, and B2B flat tax from art. 30c.
Does B2B always mean higher net cash?▾
No. B2B may increase cash flow, but shifts risk to the contractor: no employment holiday rights, different sickness protection, no employment-code protections and different benefits. The real tax rate, health contribution, ZUS and business costs matter.
Does VAT affect the employment vs B2B comparison?▾
Between active VAT taxpayers, net amounts are usually compared because VAT is settled separately. If the client cannot deduct VAT, compare the gross invoice cost.
When should disguised employment be checked?▾
When the cooperation has employment-like features: fixed place and time, subordination, no business risk and work under direction. An invoice alone does not prove that the relation is not employment.
Cash payment and fiscal register limits calculator
Check the B2B cash payment limit and the indicative fiscal register exemption threshold for consumer sales.
The limit applies to the transaction, not a single invoice.
Cash amount paid within the transaction.
Sales to individuals not conducting business activity and flat-rate farmers.
The fiscal threshold is calculated proportionally from this date to year-end.
Note: some industries and goods require a fiscal register regardless of the threshold. This calculator checks only the basic value threshold.
FAQ: fiscal register threshold and cash payments
How is the PLN 20,000 fiscal register threshold calculated?▾
If B2C sales start during the year, the threshold is proportional: PLN 20,000 x days of sales until year-end / days in the year. The calculator counts days from the first B2C sale date inclusive.
Does the fiscal register threshold apply to B2B sales?▾
Not in this basic sense. A fiscal register concerns sales to individuals not conducting business activity and flat-rate farmers. B2B sales documented by invoices usually do not enter this threshold.
When is a fiscal register required regardless of the threshold?▾
Some goods and services are excluded from the exemption, for example selected catering, hairdressing, cosmetic, mechanical, legal or tax advisory services. Check the current Polish regulation on fiscal register exemptions.
What does the PLN 15,000 B2B cash limit mean?▾
Art. 19 of the Polish Entrepreneurs' Law requires payment through a payment account when another entrepreneur is a party to the transaction and the one-off transaction value exceeds PLN 15,000. The limit applies to the transaction value, regardless of the number of invoices or payments.
What should be done if the threshold is exceeded?▾
For fiscal registers, check when the recording obligation starts and whether a transition period applies. For B2B payments above PLN 15,000, use a bank transfer or another payment through a payment account to reduce tax risk.
CO2 and car tax cost limit calculator
Check which depreciation or lease cost limit may apply to a passenger car from 2026 based on CO2 emissions.
Use the value from vehicle documents or manufacturer data.
Zero-emission cars have a separate limit.
Value compared with the tax limit.
For pre-2026 contracts, verify transitional rules.
Assumption: the calculator shows a simplified limit classification: PLN 225,000 for zero-emission cars, PLN 150,000 below 50 g/km and PLN 100,000 from 50 g/km.
FAQ: CO2 and car cost limits
What is the legal basis for passenger car cost limits?▾
For PIT taxpayers, the reference is art. 23 sec. 1 item 4 and art. 23 sec. 1 item 47a of the PIT Act. For CIT taxpayers, the corresponding rules are art. 16 sec. 1 item 4 and art. 16 sec. 1 item 49a of the CIT Act. The rules limit depreciation and lease, rental or similar charges for passenger cars.
What changes with CO2 from 2026?▾
From 2026, the PLN 100,000 limit applies to passenger cars with CO2 emissions of at least 50 g/km. The PLN 150,000 limit applies to cars below 50 g/km and the PLN 225,000 limit to electric and hydrogen cars.
Does the limit apply to operating leases?▾
Yes. The limit applies not only to depreciation but also to leases, rental, tenancy and similar agreements. In practice, the tax-deductible part of the fee is often determined by the limit / car value proportion.
Where should CO2 emissions be taken from?▾
The safest source is vehicle documentation, homologation data, the lease contract or official vehicle data. If the data is unclear, confirm it before signing, because it affects the tax cost limit.
Can pre-2026 contracts have different rules?▾
Yes. Cars entered into records or contracts signed before the change may be affected by transitional provisions. That is why the calculator flags pre-2026 years as requiring additional verification.
Results are informational and are not tax, HR or legal advice. Exemptions, transitional rules, interpretations or individual payer parameters may matter in specific situations.
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