F
Local government

Detection of an error in real estate tax calculation

Our analysis of a municipal budget near Warsaw revealed that 83 residents were paying a tax that was 14% too high due to a mistake in a resolution. Publicizing the matter led to a correction.

3400 PLN refund per house
ClientResidents of the Piaseczno Municipality
IndustryLocal government
TimelineMay–June 2024

We scrutinized a tax resolution in a municipality near Warsaw and found a mistake in a single comma. Because of this error, exactly 83 families were paying higher monthly installments for their homes without even knowing it.

BIP AnalysisMunicipal budgetTax auditCivic interventionLocal law

The challenge

In December 2023, local councilors passed new real estate tax rates. In the section concerning mixed-use residential buildings—where someone might have a small workshop or home office—an error occurred in the margin calculation. Instead of the statutory 1.15 PLN per square meter, the municipal accounting system was charging 1.34 PLN.

Residents received notices with amounts that were on average 320 PLN higher per quarter. No one protested because official letters from the municipal office are written in complex language, and most people simply pay them without checking the math. The problem affected a specific group of 83 households that had been overpaying state taxes for 5 months, which added up to a significant sum taken from neighbors' pockets.

Our approach

Our 3-person team downloaded 14 pages of documentation from the Public Information Bulletin (BIP) and began manually comparing the rates. We didn't use automation; instead, we compared the municipal table with the regulation of the Minister of Finance dated July 23, 2023. After 11 hours of analyzing Excel spreadsheets, we had evidence in black and white of where the algorithm error occurred.

Instead of looking for a political scandal, we focused on pure mathematics. We checked the land and mortgage registers for 12 random properties from this group to confirm whether the error actually translated into real transfers. Once the numbers were confirmed, we prepared a report that was understandable for everyone, not just lawyers or tax officials.

The solution

We prepared a specific letter to the mayor requesting clarification on the procedure for correcting an obvious clerical error. Instead of attacking, we showed them a ready-made solution and the correct calculations. Simultaneously, we published a short tutorial on the Frakcja Info portal: how to check your tax decision and how to write an application for a declaration of overpayment.

Heads-up: government offices rarely admit a mistake so quickly, but here the arguments were undeniable. Additionally, we sent copies of the report to 4 local councilors, whom we asked to intervene at the next budget session. We focused on ensuring that residents wouldn't have to fight the officials themselves, but would instead receive ready-to-use tools to recover their money.

Results

The office admitted the error 11 days after our publication and the submission of an official inquiry. The municipal council voted for the amendment, and residents began receiving corrected decisions and refunds to their bank accounts.

3400 PLN
Average overpayment refund per house (160m2)
83
Families who recovered their money
11 days
Time from report to municipal reaction
14%
Amount by which the tax was overcharged

Timeline

  1. May 2024
    Routine audit of tax resolutions in the municipalities of the Piaseczno district.
  2. June 12, 2024
    Detection of a mathematical error in the rate for residential and commercial buildings.
  3. June 18, 2024
    Sending the official Frakcja Info report to the Municipal Office.
  4. June 29, 2024
    Municipal council vote on the amendment correcting the tax rate.

"I was sure that the office wouldn't make a mistake. Only when Frakcja Info showed the calculations on paper did I realize I was overpaying 320 PLN per quarter. The money returned to my account in July."

Marek Wiśniewski Single-family home owner, Residents of the Piaseczno Municipality August 2024