A developer announces “-10% until the end of the month” and you cannot tell whether it is a bargain or the old price in new packaging. The answer is in data the developer must publish. With every price change the developer must give the date of the change, and in most files on dane.gov.pl each price comes with the date from which it applies. On its own website the developer must also keep earlier prices with the dates of the changes (art. 19a ust. 2 of the Developer Act, legal position as at October 2026). If the “discounted” price has applied for months, or is higher than the lowest price in the 30 days before the promotion, the price has not really fallen. You can check developer promotions in Warsaw in two places: the price list on the developer’s website and the developer’s file on the dane.gov.pl portal.
Legal basis: the Act of 20 May 2021 on the protection of the rights of buyers of residential premises or single-family houses and on the Developer Guarantee Fund (the Developer Act, ustawa deweloperska), consolidated text Dz.U. 2026 poz. 880. Legal position as at October 2026.
Three questions to ask before you reserve a flat from a promotion:
- From what date does the promotional price apply, and did it already apply before the promotion was announced?
- What did the same flat cost in recent weeks and months, in particular in the 30 days before the cut?
- Did the price per m² fall at the same floor area, or did only the total change, for example because of a new floor area, a package or a parking space?
Price transparency of developer flats: where are the date and price history?
The developer’s website. Under art. 19a ust. 1 the developer publishes on its website the price per m² of usable floor area of each unit, the prices of rooms ancillary to the unit and of rights needed to use it (if they are not included in the price of the unit), and other monetary charges, all including VAT. With each price change it updates the page “on the day of the change”, “stating the date of the change” and “keeping the information previously given, starting from the day sales began” (art. 19a ust. 2). The price history of a flat should therefore be visible on the developer’s website.
Advertising. In an advertisement, notice or offer, the developer states the address of the page with these prices (art. 19a ust. 3). A “-10%” banner should therefore carry the address of the price list where you can check the date and earlier prices.
The dane.gov.pl portal. The developer sends data once a day to the minister responsible for computerisation, and it is published on the open data portal (art. 19b ust. 1 and 3). In files that follow the ministry’s structure, each price has a column with the date from which it applies. The files are licensed under CC0. A file can change from one day to the next, so record the download date (legal position as at October 2026). From 11 November 2026 the data structure is to be set by a regulation (amendment of art. 19b, Dz.U. 2026 poz. 1077). As at 7 October 2026 that regulation had not been published in the Journal of Laws (Dziennik Ustaw).
Our catalogue. In the list of flats with the price date, the “Price as at” column shows the price date from the developer’s file, or the file date where the developer did not give one. In the Warsaw Open Price Index you will find the median price per m² in each development with the data date. We do not publish day-by-day change history, so check a flat’s history with the developer.
How to check a promotion step by step
- Save the advertisement. Take a dated screenshot and check whether the advertisement gives the address of the page with the prices.
- Find the flat in the developer’s price list. Note the price per m², the price of the flat, the date of the last change and the earlier prices.
- Download the dane.gov.pl file from the same day. Find the flat number and the date from which the price applies. We explain how to find a specific development’s dataset in our guide on how to find a specific development’s file on dane.gov.pl.
- Compare the price date with the promotion date. If the “discounted” price has applied since a day before the promotion started, the promotion did not lower the price of that flat.
- Work out the lowest price from the 30 days before the cut. If the price rose just before the promotion, a discount calculated from the raised price is smaller than it looks.
- Calculate in PLN per m² at the same floor area. A change in the total may come from a new floor area, not a new price.
- Add the extras. Check the price of the parking space and storage unit and their dates, especially when the promotion covers a “package”.
- Compare with the development’s median in the Warsaw Open Price Index. This is context, not a verdict on whether the price is a bargain.
What the developers’ files show: six example flats
Below are entries from developers’ files on dane.gov.pl. Prices are gross. We show how to read an entry. We do not know whether the developers announced these changes as promotions, and we draw no conclusions about the market from them.
Scroll the table sideways to see all columns.
| Development (district), unit | Entry in the file | What it means |
|---|---|---|
| Korkowa 146 (Wawer), units K1.01, K3.04, K3.10, K3.14 | Price per m² from 09.09.2026 against the price from 14.03.2026, floor area unchanged: PLN 16,000 → 15,600 (−2.5%), 15,600 → 15,200 (−2.6%), 16,450 → 16,000 (−2.7%), 16,600 → 16,000 (−3.6%) | This is what a cut looks like in the data: same floor area, lower price per m², new date |
| Aleja Krakowska 201 (Włochy), M2, 75.19 m² | PLN 1,258,345 (from 02.09.2025) → 1,157,926 (from 05.08.2026) → 1,052,585 (from 09.09.2026) | Two cuts 35 days apart: −9.1% against the previous price, −16.4% against the first |
| Galant Ząbkowska (Praga-Północ), unit 43, 56.45 m² | PLN 1,472,000 → 1,367,820 (both entries 11.09.2025) → 1,437,820 (14.04.2026) → 1,235,450 (28.05.2026) | Before the cut the price rose by 5.1%. Measured from the April price the cut is −14.1%, from the lowest earlier price −9.7% |
| Osiedle Śpiewających Ptaków (Wawer), house 11, 94.14 m² | PLN 835,000 (11.09.2025) → 909,000 (17.02.2026) → 949,000 (08.08.2026) → 929,000 (21.08.2026) | The 2.1% cut came 13 days after an increase. The lowest price in the 30 days before it was PLN 909,000, which is less than the price “after the cut” |
| Konopacka (Praga-Północ), KO1/C/3/120, 43.91 m² | … 860,636 (until 14.05.2026) → PLN 807,944 (15.05.2026) → 860,636 (01.07.2026) → 772,816 (31.07.2026) → 860,636 (01.09.2026) → 772,816 (02.09.2026) | A 10.2% fall from 1 to 2 September, but the same price of PLN 772,816 had applied throughout August |
| Kowalskiego 37 (Targówek) | Price per m² unchanged, while flat totals changed from −0.19% to +0.50% because floor areas were refined. Two entries were withdrawn after 1 and 10 minutes (unit 24: +1.4%, unit 27: −5.4%). Tandem parking spaces: PLN 35,000 → 55,000 from 13.08.2026 | A change in the total is not always a change in the price. An entry withdrawn after a few minutes may have been a correction. A parking space price also has a date |
Own analysis based on data from dane.gov.pl. Files: Korkowa 146 and Kowalskiego 37 of 6 October 2026, Konopacka of 3 October 2026 (price list status for every day from 10.07.2025 to 02.10.2026), Aleja Krakowska 201 and Galant Ząbkowska of 3 October 2026, Osiedle Śpiewających Ptaków of 4 October 2026. Percentages are our own calculations.
The Konopacka file shows that on 1 September 2026 the price rose for 30 flats, and on 2 September it fell for 28. A one-day return of a price may be a data entry error. The file cannot settle this, but do not use a price that applied for a single day in comparisons. In the same file, 15 flats with unchanged floor area were cheaper on the last day of the file (2 October 2026) than on the first day they appeared in it (median −9.3%). That is one development and 15 flats, not a picture of the market.
How much price history is really in the files?
Less than you might think. In the 22 developments in our catalogue that have flats from dane.gov.pl files, there were 960 flats on offer (files downloaded on 4 October 2026):
Scroll the table sideways to see all columns.
| What the file contains | Flats | Developments |
|---|---|---|
| Date from which the price applies | 726 (75.6%) | 18 of 22 |
| of which date earlier than 1 September 2026 | 595 | — |
| At least one earlier price of the flat | 42 (4.4%) | 6 |
| At least two earlier prices | 12 | 4 |
| Price list status for every day | 18 | 1 (Konopacka) |
Own analysis based on data from dane.gov.pl (files downloaded on 4 October 2026).
The price date was missing from the files of four developments: Apartamenty Płużnicka, Konopacka (where the developer instead publishes the price list status for every day), Rezydencja Liwska and Osiedle Sprawna. In most cases the file shows only the current price with its date, so earlier prices have to be read on the developer’s website, where art. 19a ust. 2 requires them.
For this reason we do not give an “average discount” or a share of developers who raise prices before a promotion. The history of 42 flats in 6 developments is too little for such conclusions.
Does the “lowest price in the last 30 days” rule apply to a promotion?
It is not clear. The rule comes from the Act on informing about prices of goods and services (consolidated text Dz.U. 2023 poz. 168). When a price is cut, the lowest price from the 30 days before the cut is given next to it (art. 4 ust. 2), including in advertising that shows a price (art. 4 ust. 5). The Act covers “goods”, meaning a thing, and also transferable property rights (art. 3 ust. 1 pkt 4). However, it does not apply to price information regulated by separate statutes (art. 2), and the Developer Act regulates price information for developer flats (art. 19a). The explanations of the President of UOKiK of 8 May 2023 speak of all traders promoting goods or services but do not mention real estate. Legal position as at October 2026.
In practice, do not assume the developer will give you the lowest price from the 30 days. Work it out yourself from the history on its website. The example of house 11 in Osiedle Śpiewających Ptaków in the table above shows why. The price of PLN 929,000 from 21.08.2026 is lower than the previous one, but higher than the PLN 909,000 that still applied on 7 August.
A promotion on a package, parking space or “discount from the list price”
A discount does not always concern the price per m². It may be a “parking space on promotion” or a “storage unit at half price”. The prices of rooms ancillary to the unit and of necessary rights, if not included in the price of the unit, and other monetary charges, are given by the developer on its website including VAT (art. 19a ust. 1 pkt 2 and 3). Each of these items is checked the same way as the price of the flat: date and earlier price. An example from the table: at Kowalskiego 37 the price of tandem parking spaces rose from PLN 35,000 to 55,000 from 13 August 2026. A discount on the flat combined with a dearer parking space may not change the total. We describe what to add to the price of the flat in our guide on price list extras to add to the price.
With a “discount from the list price”, remember that in developer agreements concluded from 13 February 2026 the price of the unit is defined as the product of the usable floor area and the price per 1 m² (art. 5a). Ask for the discount to be visible in the price per m², because that is what goes into the contract.
If you are a foreign buyer: what this means in practice
The developer’s price list, the advertisement and the dane.gov.pl file are in Polish, and those are the documents you need to check. On the day of signing, therefore, save the price page with the date visible and download the file from dane.gov.pl: any discrepancy you notice must be reported in writing before you sign (art. 19a ust. 6 gives you the right to demand a contract at the most favourable price). Do not count on the developer volunteering the lowest price from the 30 days. A dated screenshot of the advertisement is for you, as evidence of what the banner actually promised. We serve clients in 7 languages and will explain what each column of the file and each entry in the price list means.
What if the price in the contract or the advertisement raises doubts?
Contract price higher than the price list. If the price given on the developer’s website differs from the price at the time the contract is concluded, you may demand a contract at the price most favourable to you (art. 19a ust. 6). On the day of signing, save the price page with the date visible, download the file from dane.gov.pl and report the discrepancy in writing before you sign.
Advertising that may mislead. The Act on Counteracting Unfair Market Practices (consolidated text Dz.U. 2023 poz. 845) states that a misleading action may concern, among other things, “the price, the way the price is calculated or the existence of a special price advantage” (art. 5 ust. 3 pkt 5). Disseminating true information in a misleading way can also mislead (art. 5 ust. 2 pkt 2), as can a misleading omission (art. 6 ust. 1). Under all circumstances “bait advertising” is unfair (art. 7 pkt 5). Whether a particular promotion breaches these provisions is for UOKiK or a court to decide, not the buyer or an agent.
No prices or price history on the website. Breaching the duties in art. 19a is a practice infringing collective consumer interests (art. 19a ust. 5). The President of UOKiK may impose a fine of up to 10% of the previous year’s turnover for it (art. 106 ust. 1 pkt 4 of the Act on Competition and Consumer Protection, Dz.U. 2025 poz. 1714). Legal position as at October 2026. We describe where to report an irregularity in our guide on flat price transparency. What changes in developers’ files from 11 November 2026 is covered in a separate guide.
FAQ
How can I tell whether a developer discount is a real price cut?
Check three things: the date the promotional price took effect, the earlier prices of the same flat, and the price per m² at the same floor area. A developer must show price changes with their date on its website and keep earlier data from the start of sales (art. 19a ust. 2 of the Developer Act, Dz.U. 2026 poz. 880, legal position as at October 2026). If the “discounted” price already applied earlier, or is higher than the lowest price in the 30 days before the cut, the price has not really fallen.
Must a developer state the lowest price from the 30 days before a promotion?
This is not settled. The duty to state the lowest price from the 30 days before a cut comes from the Act on informing about prices of goods and services (Dz.U. 2023 poz. 168, art. 4 ust. 2 and 5). However, that Act does not apply to price information regulated by separate statutes (art. 2), and the price transparency of flats is regulated by the Developer Act. Legal position as at October 2026. You can work out the lowest 30-day price yourself from the price history on the developer’s website.
Where can I find the date a flat’s price took effect?
On the developer’s website next to the price of the flat, and in the developer’s file on the dane.gov.pl portal. In files that follow the ministry template, each price has a column with the date from which it applies. In the 22 developments in our catalogue, that date was given for 726 of 960 flats on offer (files downloaded on 4 October 2026).
What should I do if the contract price is higher than the price list?
If the price on the developer’s website differs from the price at the time the contract is concluded, you may demand a contract at the price most favourable to you (art. 19a ust. 6 of the Developer Act, legal position as at October 2026). On the day of signing, save the price page with the date visible, download the file from dane.gov.pl and report the discrepancy in writing before you sign.
Can a “until the end of the month” promotion be misleading?
It can, if it misleads as to the price, the way it is calculated or the existence of a special price advantage (art. 5 ust. 3 pkt 5 of the Act on Counteracting Unfair Market Practices, Dz.U. 2023 poz. 845). True information presented in a misleading way can also mislead (art. 5 ust. 2 pkt 2). Whether a particular promotion breaches the law is for UOKiK or a court to decide.
Spotted a flat on promotion and booked a visit to the developer’s sales office? Write to us before you go. We will register you with the sales office before your first visit and go there together. Beforehand we will check the flat’s price history in the developer’s price list and on dane.gov.pl, go through the information prospectus and the draft contract with you, and point out what to ask the developer or a lawyer. A buyer on the primary market does not pay us a fee. Our remuneration on the primary market comes from agreements with developers.
Jawno · +48 692 649 839 · infojawno@gmail.com
This text is for information only and is not legal advice. Legal position as at October 2026.