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Guide18 September 20265 min read

Premium SMS or a 900–909 number on your bill? What to do

You look at the bill and find a charge for an SMS or a call to a number you have never dialled. Premium lines with the 900–909 prefix and so-called Premium SMS are a common puzzle on bills, because they are not a service of the operator itself, but paid third-party content that the operator only intermediates.

What premium SMS and 900–909 numbers are

Numbers starting with 900, 905, 906, 908 or 909 are reserved under the numbering plan for so-called services with an expressed price (they used to be commonly called audiotext services as well). Behind the prefix sits a specific paid service, for example an information line, a contest or a vote. Premium SMS work in a similar way. The service is offered and operated by the content provider, not by your mobile operator. For voice lines the price is encoded directly in the number, which is why it differs substantially from number to number. You will find it in the operator’s price list or directly with the service provider.

The operator in this relationship only acts as a technical intermediary: it connects the call or delivers the SMS and collects the price that belongs to that number. The provider of the service, not the operator, is responsible for the content, quality or fairness of the offer of the service itself.

Who is actually responsible for the charge

This distinction determines where to take the complaint.

If it is disputed whether the connection or the delivery of the SMS took place at all, meaning the operator is charging you for a connection that in your view never happened, it is a technical question of the electronic communications service provided. You handle that with a complaint to the operator and, if unsuccessful, to the Czech Telecommunication Office (Český telekomunikační úřad, ČTÚ), the same as with a regular billing complaint.

If the content, price or fairness of the premium service itself is in dispute, meaning you never knowingly ordered a paid subscription via SMS, or you received a message with a hidden, unclearly communicated fee, it is a dispute with the provider of that specific service, not with the operator. You then file the complaint directly with the provider. The ČTÚ does not handle such disputes. If the provider does not uphold the complaint, you can turn to the Czech Trade Inspection Authority (Česká obchodní inspekce, ČOI). It handles consumer disputes out of court as well and also acts against misleading or aggressive commercial practices.

The specific provider for a given prefix can be looked up at the Association of Mobile Network Operators (Asociace provozovatelů mobilních sítí, APMS), the association of O2, T-Mobile and Vodafone, which sets rules of conduct for premium SMS services and mobile payments. On the Plať mobilem website, which APMS operates, you will find a form to look up the provider and submit a complaint at platmobilem.cz/jak-a-kde-reklamovat-sluzby.

How to have premium services blocked

The most effective defence against repeated unexpected charges is to have Premium SMS and paid lines blocked with the operator straight away. According to the Czech Telecommunication Office, this is possible with every operator, without exception. You usually arrange it through the customer line, the app or the operator’s self-service portal, and along with premium SMS and lines you can also block other payments to third parties via the mobile phone. After the block, similar items will stop appearing on the bill, which in practice is simpler than complaining about each individual payment after the fact.

What to do when the item has already been charged

  1. Find out the exact number or prefix to which the payment was directed, and look up what service and provider it is (e.g. in the service catalogue on the Plať mobilem website).
  2. Decide whether the very existence of the connection is in dispute (a technical question for the operator/ČTÚ), or the content and fairness of the service (a question for the service provider/ČOI).
  3. If it is about the connection, file a written complaint about the bill with the operator no later than 2 months from the day the bill arrived. The deadline and the procedure follow the same rules of the Electronic Communications Act as for other items on the bill.
  4. The operator must handle the complaint within 1 month of delivery. If it rejects it or does not respond, you have 1 month to file an objection with the ČTÚ.
  5. Ask the operator at the same time to block premium services, so that the same situation does not repeat.

What to do next

Describing to the operator exactly which number and which disputed item is involved, and referring to the correct statutory deadline, takes more work than it might seem at first glance. A complaint that contains both is harder to brush aside.


Legamik is not a law firm and does not provide legal advice. In complex disputes we recommend consulting a lawyer.

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