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Data sources

This English version is a translation provided for information. Only the Hungarian text is legally binding: the Hungarian original.

Where the matches come from, on what terms we use them, and what each source is good for. On one page, so that you do not have to work it out from the small print in the footer.

Why this page exists. Address data is worth as much as we know about where it comes from. If it is not visible which source a postal code came from and what date the dataset is from, the match cannot be checked. That is why we list the sources by name, together with their licences.

Adatka is built on several external data sources, each of which has its own terms of use. Some licences — for example CC BY 4.0 and the ODbL — require that, when the data is used, the source must be named and the licence must also be referenced. Attribution also helps to make it verifiable where a match comes from and on what terms it may be used further.

Naming a source does not mean that the organisation in question has approved or endorses Adatka, or regards it as its official service.

KSH Gazetteer (Helységnévtár)

Official settlement names, settlement identification codes, county and district (járás) classification. It provides the administrative framework: if the name of a settlement occurs in more than one spelling, the Gazetteer decides which one is official.

GeoNames

An international database of geographical names: postal codes, coordinates, time zone. With us it plays a supplementary role — it helps where the official source gives no coordinates.

OpenStreetMap

Streets, house numbers and geometry. Coverage varies greatly from settlement to settlement: it is good in towns and cities, and may be incomplete in smaller villages. We do not smooth this over — if a house number is missing, the service says so.

Magyar Posta Partner Extra

Postal code and street register from Magyar Posta, based on the dataset of 21 September 2026.

If the postal data differs from the value in another source, we also keep the other value; we do not delete it without trace. If the postal code entered differs from the postal code of the address found, the response flags this separately.

National Election Office (Nemzeti Választási Iroda) — polling district address dataset

The address dataset of the electoral districts (Körzetállomány): settlement, postal code, street and house number, without coordinates. With us it serves two purposes. First, it tells us whether the house number entered exists on the given street. If it exists but we have no coordinates of our own for it, the response gives the house number, while the coordinates are not those of the house — the response flags this with a separate match level and with the precision of the coordinates. Second: if Magyar Posta and OpenStreetMap spell the name of a street differently, it helps, as a witness, to choose between the two spellings.

What all this means for the matches

The exact terms of the licences, the source-by-source list and the OpenStreetMap database licence, which is passed on (share-alike), are in section 3 of the Legal notice. This page says the same thing in plain language; it does not replace it.

adatka is not an official register. The official Hungarian address register is the Central Address Register (Központi Címregiszter). We compare the public sources with one another and tell you which one we worked from — that is a different task, and it does not replace official data.

Updated: 5 October 2026 (settlement parts: the role of OpenStreetMap and of the KSH Gazetteer supplemented) · Clarification: 14 October 2026 (the terms of use of the KSH Gazetteer: under the KSH's published terms, with attribution; the source, terms of use, dataset and role of Magyar Posta Partner Extra — in a list, like the other sources) · Amended: 20 October 2026 (formatting: emphasis removed from running text; the content did not change)