My internet is slower than promised: what can I do in Czechia?
Your contract must state concrete speeds. Fixed internet: maximum, normally available (at least 60% of the advertised speed, reached 95% of the day) and minimum (at least 30% of advertised). Mobile internet: estimated maximum and advertised speed.
Your contract states the speeds your provider promises. If the real speed falls clearly and repeatedly below them, you may be able to pay less or end the contract. A measurement with the official tool, where there is one, is the strongest proof.
📜 The rules in Czechia
What you can do
Complain (reklamace) to your provider within 2 months with your measurements, asking for the fault to be fixed and a proportionate price cut (§ 64(12)). If rejected or not settled within 1 month, object to ČTÚ within 1 month (fee 100 Kč).
The details
- Measure with ČTÚ-NetTest. For a complaint about fixed internet use its certified measurement: a computer connected by cable directly to the router or modem, not over Wi-Fi. You get the result as a PDF. (nettest.ctu.gov.cz)
- Fixed internet: you can complain about a big lasting deviation (below the normally available speed for over 70 minutes), a big recurring one (at least 3 drops of 3.5+ minutes within 90 minutes) or an outage (below the minimum speed). (ctu.gov.cz)
- Mobile internet: a big lasting deviation is a drop below 25% of the advertised speed for over 40 minutes; a big recurring one is at least 5 such drops of 2+ minutes within 60 minutes. (ctu.gov.cz)
- ČTÚ runs NetTest as the certified monitoring mechanism under the EU open-internet rules. Certified measurement also works in the Android app, but not on iOS. (ctu.gov.cz)
- The law's right to cancel free of charge over big lasting or recurring deviations (§ 63b(6)) does not cover internet access services. (e-sbirka.gov.cz)
Český telekomunikační úřad (ČTÚ)
Telecom regulator: consumer information, objections to how a provider handled your complaint, and other disputes with providers.
Official speed test official
ČTÚ-NetTest
Its certified measurement produces a PDF you can use in a complaint to your provider. For a complaint about fixed internet ČTÚ requires the certified mode, with your computer connected to the router or modem by cable, not Wi-Fi.
🪜 Step by step
- Find the promised speedsYour contract summary lists the speeds, often as a maximum, a normally available and a minimum speed.
- Measure properlyUse a cable instead of Wi‑Fi, close other devices and measure several times on different days, with the official tool if there is one.
- Report it to the providerSend the results, ask for the problem to be fixed and keep a copy of everything you send and receive.
- Use your rightsIf nothing improves, ask for a lower price or to end the contract, and go to the dispute body if the provider refuses.
📇 Who to contact
Sponsor this page → One labelled block, €100 a month. Founding price €75 until 31 January 2027.
❓ Questions
Does a quick speed test in an app count?
It helps you spot a problem. As proof, a measurement made the way the regulator or your contract describes carries much more weight.
Does this apply to mobile internet too?
Mobile speeds change with place and network load, and the rules for mobile are often different. See the rules for Czechia on this page.
Is slow Wi‑Fi the provider’s fault?
Not always. Walls, distance and old devices slow Wi‑Fi down. Measure with a cable first.
📎 Sources
- ctu.gov.cz →
- nettest.ctu.gov.cz →
- ctu.gov.cz →
- ctu.gov.cz →
- e-sbirka.gov.cz →
- ctu.gov.cz →
- ctu.gov.cz →
- ctu.gov.cz →
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