Since 11 July 2025, a Polish developer can no longer keep its price list in a drawer. Prices of the units on offer have to be on its own website together with their history, and once a day the data goes to a minister who publishes it as open data. From 11 November 2026 the way this daily transfer works changes.
Here we set out what the law actually says, where manual work in Excel makes prices drift apart, and what a system could look like in which the website, the data transfer and the sales documents are fed from one source. We write as a small firm that builds custom systems. The part about automation is our proposal, not a project we have already delivered for a developer.
This is not legal advice; it is worth checking the details of your own situation with a lawyer or an accountant.
What a developer publishes on its website
The obligation was introduced by the act of 21 May 2025, published in Dz.U. (Dziennik Ustaw, the Polish Journal of Laws) 2025 item 758. It added articles 19a and 19b to the Polish Developer Act (ustawa deweloperska). The rules apply from 11 July 2025, and developers who had started selling before that date got two months from that date to adapt.
The developer runs its own website and publishes on it, for every unit on offer:
- the price per square metre and the price of the whole property or its part;
- the price of ancillary rooms or necessary rights, if they are not included in the unit price;
- other cash payments the buyer has to make.
All amounts are given including VAT. We stick here to what the provision says and do not add requirements that are not in it.
Price changes and history
When a price changes, the website is updated on the same day and shows the date of the change. Earlier prices are kept from the start of sales, so the page shows not only today’s price but its whole path.
Adverts, listings and offers
In adverts, listings and offers the developer gives the address of the page where the prices are. So the price list is not a hidden subpage that only the sales team knows about: adverts, listings and offers all point to it.
The price on the website and the price in the contract
If the price on the website differs from the price in the contract, the buyer may demand a contract at the price most favourable to them. This provision shows most clearly why a price should come from one place.
The daily data transfer and the change from 11 November 2026
Once a day the developer passes the data to the minister responsible for digital affairs, and the minister publishes it on the data portal. The act gives no web address; it refers to the data portal as defined in the Polish open data act, and that portal is dane.gov.pl, the Polish open data portal. The act calls this data high value data.
The act of 17 July 2026 (Dz.U. 2026 item 1077) amends article 19b from 11 November 2026. The data will be passed as an electronic document, following a data structure set by the minister in a regulation. The act also provides for document templates made available on the portal.
We do not describe that structure here. It is set by the regulation, and a description written without it would be guesswork. As of 21.10.2026: if you are planning changes to the transfer, base them on the regulation and the templates on the portal, not on second hand descriptions.
Who enforces the rules
The act treats a breach of articles 19a and 19b as a practice that infringes the collective interests of consumers, which makes it a matter for the President of UOKiK, the Polish competition and consumer protection authority. The 2025 act itself does not set the amount of penalties; it refers to the Polish act on competition and consumer protection.
Why a manual Excel file is a risk
A developer with a few units on sale can meet this obligation with a carefully kept spreadsheet, and there is nothing wrong with that. The trouble starts when a price lives in several places at once: in the sales team’s spreadsheet, on the website, in listings, in PDF offers, in the draft contract and in the file for the daily transfer.
Let us assume that on a Friday afternoon the sales team lowers the price of three units in the spreadsheet. The person who updates the website is on holiday, so the change only reaches it on Monday. On Saturday a client receives a PDF offer that still shows the old price. Each delay is small, but together they produce a price that nobody can point to with certainty.
- An overwritten cell. A spreadsheet holds a price, not a history. Whoever types a new price over the old one deletes what the law says must be kept.
- Two versions of the file. “pricelist_final” and “pricelist_final_2” on two computers are two sources of truth.
- A forgotten transfer. A daily duty that relies on one person’s memory will not survive a holiday or a sick day.
- No date of change. Without a date you cannot show since when a price applied, nor rebuild the history.
- A contract from another file. If the price in the draft contract comes from a different source than the website, any discrepancy works in the buyer’s favour.
One source of data: what the system could look like
The answer is not to retype faster. It is to record a price once and let the website, the transfer and the documents only read it. We can build such a system. This is how we would design it:
- A register of projects and units. Buildings, units, floor areas, ancillary rooms and other payments in one database, with an import from your current Excel sheets.
- A price as a history, not a field. Every change is a new entry with a date and an author. Nobody overwrites old entries, so the history from the start of sales builds itself.
- A price page built from the same data. An approved price change appears on the website straight away, with no separate step.
- A daily transfer nobody has to remember. Once a day the system prepares the data in the form the rules require, and if the transfer fails, it alerts a named person.
- Offers, unit sheets and contract data from the same record. The PDF for the client and the draft contract take the price from the same place as the website.
- Roles and permissions. Only someone with the right to do so can change a price, and every change leaves a trace.
- The transfer as a separate module. When the data structure from the regulation starts to apply, or later changes, you fix one place rather than the whole system.
We have already built some of these parts in another context. The system for managing a commercial real estate portfolio, which we built in 11 weeks, in four stages each closed with an acceptance report, includes PDF document generation, Excel import and export, and user roles and permissions. You can read about the project in our case study. We have not yet built a price transparency module for a developer, and we do not pretend otherwise.
AI is not needed here. This is a job for a sound data model, not for a language model. Where AI does make sense in real estate, and why a person always checks what it reads, we cover in our post on AI reading lease agreements.
A checklist for developers
- List every place where a unit’s price lives today: spreadsheets, the website, listings, offers, draft contracts, the transfer file.
- Choose one source the others should take the price from, and the person responsible for changes.
- Check that for every unit you have the price history from the start of sales, with the date of every change.
- Check that the website shows the price per square metre, the total price, ancillary rooms or rights and other payments, all including VAT.
- Check that a price change reaches the website on the same day, including on a Friday evening.
- Go through adverts, listings and offers to see whether they give the address of the price page.
- Agree who does the daily data transfer, how, and what happens when it fails.
- Plan how to adapt the transfer to the changes from 11 November 2026, and follow the regulation and the document templates on the portal.
- Go through your process with a lawyer before you consider it done.
Let us talk about your price list
If the prices of your units live in several files today, write to us in a few sentences about how a price travels from the decision to change it to the website and the contract. We will reply with where it makes sense to start and arrange a free consultation.
You can put together an approximate cost of the modules in our approximate price builder. It is approximate; the quote is individual, because it depends on your processes.
