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Mobile Operator in Czechia: Which One to Choose in 2026

Updated: 18.07.2026

Which mobile operator to choose in Czechia depends on two things: how much data you need and whether you're willing to sign a contract. Short answer: for no-strings-attached savings, go with a virtual operator like Kaktus or Mobil.cz — starting at 250 Kč a month on the T-Mobile network — while for unlimited data and family discounts, head to O2, T-Mobile, or Vodafone for a contract plan (paušál), where promotional unlimited plans start at roughly 250 Kč a month.

This guide covers how the telecom market works, a 2026 price comparison, the difference between paušál and prepaid cards, the documents needed for a contract, family plans, eSIM, and number porting.

How the market works: three networks and the virtuals

Czechia has three physical mobile networks — O2, T-Mobile, and Vodafone. Every other provider is a virtual operator (MVNO) leasing capacity from one of them: Kaktus and Mobil.cz run on T-Mobile's infrastructure, while BLESKmobil runs on O2's. Signal quality on a virtual operator is identical to that of its "parent" network — the difference lies only in price and service.

LTE coverage across all three networks is nearly universal — around 99% of the population. By 2026, 5G reaches roughly 96% of residents, with comparable coverage among all three operators. In Ookla's independent ranking for the second half of 2025, O2's network was named the country's fastest 5G network, and it's the only one of the three running in public 5G SA mode with low latency. To check coverage at a specific address, use the regulator ČTÚ's map at vportal.ctu.gov.cz.

Big three or virtual operator

2026 price comparison: basic plans

OperatorPlanDataMonthly price
O2NEO+ Modrý6 GB129 Kč with a 24-month commitment (standard price 529 Kč)
O2NEO+ Stříbrnýunlimited up to 15 Mb/s249 Kč on promotion
T-MobileNextU 12 GB12 GB198 Kč with discount
T-MobileNextU Lunlimited up to 20 Mb/s282 Kč with discount
T-MobileNextU XLunlimited at full 5G speed362 Kč on promotion, standard price around 905 Kč
VodafoneBezLimitu Munlimited up to 8 Mb/s330 Kč on promotion (standard price 799 Kč)
KaktusNeřešto for 2505 GB250 Kč
KaktusNeřešto for 35010 GB, then unlimited at 2 Mb/s350 Kč

Prices are current as of mid-2026 and include promotions; operators regularly change their terms, so before signing up, check the current ceník on the operator's website or on comparison sites like Tarifix and Ušetřeno.cz.

An important nuance: "unlimited data" in Czechia means unlimited volume, but with a speed cap (FUP) of 8, 15, 20, or 40 Mb/s. Only the most expensive plans, like NextU XL, offer full 5G speed.

Virtual operators: Kaktus, Mobil.cz, and the fate of Sazkamobil

Kaktus

A youth-oriented project by T-Mobile, running since 2013. The classic setup is a prepaid card with add-on packages: calls at 2.50 Kč a minute, SMS at 1.50 Kč, and data purchased separately in bundles. There are also auto-renewing Neřešto prepaid plans: 250 Kč gets you 5 GB plus 100 minutes or SMS, 350 Kč gets 10 GB, and 450 Kč gets 20 GB; on the 350 and 450 plans, once the data runs out, the internet doesn't cut off but slows to 2 Mb/s. Kaktus is known for its dobíječka promotions, when your credit top-up gets doubled.

Mobil.cz

A virtual operator run by the MAFRA media group on the T-Mobile network. Its format is cheap prepaid: a SIM for 200 Kč that already includes 200 Kč of credit, small call and data bundles, and eSIM support. Keep in mind: credit is valid for 6 months, and a number with no top-up is deactivated after 12 months.

Sazkamobil no longer exists

If someone recommends Sazkamobil, that advice is outdated. Vodafone bought out this virtual operator and permanently shut down the brand in September 2025: around 200,000 customers were migrated to the Oskarta prepaid card on the Vodafone network, keeping their numbers.

Paušál or prepaid card

A prepaid card (predplacená karta) is sold freely — in stores, trafika kiosks, supermarkets, and gas stations, usually with no documents required. It's the best option right after moving to Czechia, for children, and for occasional calls. If you're still settling in, check our checklist of first steps after moving.

The main catch with prepaid is expiring credit: it's typically valid for 6 months, or 12 months with a larger top-up (500 Kč or more with O2), and an inactive number is eventually deactivated by the operator. Paušál offers better value in terms of data and doesn't require tracking your credit — you're billed monthly, most conveniently via inkaso, an automatic debit that requires a Czech bank account.

What you need for a contract (paušál)

  1. ID document: EU citizens need only a passport or občanský průkaz (ID card); citizens of third countries need a foreign passport plus a biometric residence permit card (povolení k pobytu).
  2. A second photo ID may be requested if you're getting a phone on installment or a plan with a large discount.
  3. Rodné číslo — the Czech personal ID number: the operator will ask for it if you've been assigned one; without it, signing up is usually still possible with just a passport, but rules vary by operator — check at the pobočka (branch).
  4. Payment method — card or inkaso from a bank account.

All three major operators let you sign up for a plan online with identity verification via BankID or Identita občana. New customers with no payment history are sometimes offered a deposit (jistota) or asked to prepay several months in advance — check the terms beforehand. If the contract in Czech raises questions, translators can help.

Family plans: where the real savings are

If your family has two or more numbers plus home internet, bundling services is almost always cheaper than separate plans. We have a dedicated guide on choosing a home provider — home internet in Czechia.

A separate SIM for a child is most often needed once school starts — operators offer special prepaid options for kids, like O2 GO Junior with spending controls.

eSIM and number porting

In 2026, eSIM is supported by O2, T-Mobile, and Vodafone, plus virtual operators Kaktus and Mobil.cz. The profile is issued through the app (Moje O2, Můj T-Mobile, Můj Vodafone) or a QR code; eSIM plans are the same as for a physical SIM, and issuing or replacing one is usually free. This is handy when moving — no need to wait for a card in the mail.

Number porting (přenos čísla) to another operator: request a porting authorization code (ověřovací kód účastníka) from your current operator and pass it on to the new one — they'll handle the rest. By law, porting is free and takes a maximum of 2 business days, and your old operator's plan is automatically terminated in the process.

FAQ

Which operator in Czechia is the cheapest?

For plans with a decent amount of data, the virtual operators win: Kaktus Neřešto from 250 Kč or Mobil.cz's bundles. For occasional calls, prepaid is cheapest — Oskarta or Twist, where you only pay for what you use.

Can I buy a SIM card without a residence permit or documents?

Yes. Prepaid cards are sold freely at trafika kiosks, supermarkets, and stores, and a passport usually isn't required. Documents are only needed for a contract paušál plan.

Is "unlimited" data really unlimited?

In terms of volume, yes — there's no download cap. But FUP applies: speed is capped at the plan's threshold — from 8 to 40 Mb/s — with full 5G speed reserved for the top-tier plans.

Who has the best network and 5G?

LTE coverage across all three networks reaches about 99% of the population, and 5G around 96%. According to independent Ookla measurements for the second half of 2025, O2 has the fastest 5G network. What matters most is your specific address: check it on the ČTÚ coverage map before deciding.

How much does number porting cost, and how long does it take?

Porting is free and by law takes no more than 2 business days. You only need the porting code from your current operator.

Does a Czech SIM work when traveling in the EU?

Yes, "roam like at home" within the EU is included in every plan: calls and SMS with no extra charge, while data is subject to a fair-use limit — each plan has its own roaming data allowance, listed in the ceník.

Is it worth agreeing to a 24-month úvazek?

Contract discounts are significant, but early termination comes with a penalty owed to the operator. If your plans for staying in Czechia are still uncertain, start with a virtual operator or a prepaid card with no commitment — you can leave whenever you like.

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