O2 eSIM — coverage, plans & network
Europe
Key highlights
- O2 brand launched in 2002; in Germany it is Telefónica's O2 Telefónica
- O2 Telefónica is Germany's largest mobile operator by SIM count, with roughly 45 million mobile lines
- O2 Slovakia, launched in 2007, is part of the PPF-owned O2 Czech Republic group
- German 3G was switched off at the end of 2021; the network is now 4G/5G-focused
- AviaeSIM travel eSIMs connect to the O2 network in both Germany and Slovakia
About the operator
O2 is one of Europe's best-known mobile brands. AviaeSIM prepaid travel eSIMs connect to the O2 network in Germany and Slovakia, with instant QR activation and no roaming bills. Launched in 2002, the O2 name is today used by several separate operators: in Germany it belongs to Telefónica (O2 Telefónica), O2 Slovakia is part of the PPF-owned O2 Czech Republic group under a brand licence, and the UK's O2 is the separate Virgin Media O2.
In Germany, O2 grew out of Viag Interkom and, after absorbing E-Plus in 2014, became the country's largest mobile operator by SIM count, with roughly 45 million mobile lines. O2 Slovakia entered the market in 2007 as a challenger and has grown into one of the country's most liked operators, known for simple, transparent tariffs.
For travelers this matters because an AviaeSIM plan for Germany or Slovakia rides on major national infrastructure — O2 Telefónica's 4G/5G grid across Berlin, Munich and the rest of the country, and O2 Slovakia's network centred on Bratislava — without the identity registration a local German SIM requires.
- Founded
- 2002
- Headquarters
- United Kingdom
- Group
- Telefónica (Germany); PPF Group (Slovakia)
- Network
- 4G, 5G
- Subscribers
- ~45M mobile lines (O2 Germany)
Network & technology
In Germany, O2 Telefónica runs nationwide 2G, 4G/LTE and 5G, having switched off 3G at the end of 2021; its 5G now reaches the large majority of the population, strongest in cities such as Berlin, Hamburg, Munich and Frankfurt, while rural speeds historically trailed Deutsche Telekom and Vodafone before heavy recent investment narrowed the gap. O2 Slovakia operates 4G with near-national population coverage plus a growing 5G footprint centred on Bratislava, Košice and other regional cities.
Reputation & market position
In Germany, O2 has long been the value-oriented member of the big three networks and has climbed sharply in independent German network tests in recent years after sustained investment. O2 Slovakia is regularly ranked among the country's most-liked operators and built its reputation on fair, no-nonsense tariffs. Note that O2 UK (Virgin Media O2) shares only the brand — it is a different company on a different network.
Pros
- Germany's largest mobile network by SIM count, with strong 4G/5G in cities
- O2 Slovakia is known for simple, transparent tariffs and high customer satisfaction
- Excellent big-city performance in Berlin, Munich, Hamburg and Bratislava
- No German ID registration needed when you use an AviaeSIM travel eSIM on O2
Cons
- Rural German coverage and speeds have historically trailed Deutsche Telekom and Vodafone
- Busy-hour congestion is still reported in some dense German urban areas
- The O2 brand is split across unrelated owners, so UK O2 information does not apply to Germany or Slovakia
Available plans
Countries covered
Get your Slovakia eSIM from AviaeSIM — instant QR activation, no roaming fees.
How to activate
- 1Choose your destination and a plan on the O2 network
- 2Pay and receive your eSIM QR code by email
- 3Scan the QR code in your phone's settings to install it
- 4Turn on data roaming for the eSIM when you arrive
Frequently asked questions
How do I get an O2 eSIM?
O2 Germany issues eSIM profiles to its own customers through the Mein O2 app, website or shops, and German law requires identity verification before any local SIM or eSIM is activated. O2 Slovakia offers eSIM to its subscribers too. If you only need data for a trip, an AviaeSIM prepaid travel eSIM connects to the O2 network and arrives by email as a QR code in minutes, with no registration or store visit.
How much does an O2 eSIM cost?
For existing O2 customers in Germany or Slovakia, swapping a plastic SIM for an eSIM is usually cheap or free — the real cost is the monthly tariff, which varies by market and changes often, so check O2's local site. An AviaeSIM travel eSIM on the O2 network works differently: you prepay once for a fixed data package, with no contract, monthly fee or roaming charges.
Does O2 Germany support eSIM?
Yes. O2 Telefónica in Germany supports eSIM across modern iPhones, Android phones, watches and tablets, and existing customers can convert their SIM digitally. New customers must complete Germany's mandatory ID verification first. Visitors who just need mobile data can skip that entirely with an AviaeSIM prepaid travel eSIM that uses the O2 Germany network — activate it before you fly and it connects on landing.
Is O2 the same company in Germany, Slovakia and the UK?
No. The O2 brand is used by separate companies: O2 Telefónica in Germany belongs to Spain's Telefónica, O2 Slovakia belongs to the PPF-owned O2 Czech Republic group under a brand licence, and O2 in the UK is Virgin Media O2. AviaeSIM's O2-network travel plans cover Germany and Slovakia, so information about UK O2 tariffs does not apply here.
Useful links
Other operators
Information updated: 2026-07