Lake Constance Roaming: Germany, Austria and Switzerland (2026)

A day on Lake Constance, the Bodensee, can take in three countries: Lindau in the morning, a boat to Bregenz, Kreuzlingen in the evening. Germany and Austria are in the EU's Roam Like at Home area, Switzerland is not, and out on the water a phone can connect to a network from any of the three.

This guide explains roaming between Germany, Austria and Switzerland around Lake Constance: the three shores, the trap on the boats, Liechtenstein and one plan for all three.

Key facts for Lake Constance

EU roaming: Germany and Austria are covered by Roam Like at Home; Switzerland is not
On the water: a phone can connect to a German, Austrian or Swiss network
One plan for all three: the Europe plan covers Germany, Austria and Switzerland, plus Liechtenstein
Emergency numbers: 112 in all three; police 110 in Germany, 133 in Austria and 117 in Switzerland
Embassies: mostly in Berlin, Vienna and Bern

Three shores, two roaming rules

Konstanz, Lindau and Friedrichshafen are on the German shore, Bregenz on the Austrian one, and Kreuzlingen and Romanshorn on the Swiss one. On an EU SIM, German and Austrian networks are billed as at home and a Swiss one as roaming outside the EU: some operators include Switzerland, many charge for it.

Visitors with a SIM from outside the Roam Like at Home area usually pay roaming in all three countries unless their tariff includes them. A Telcomia Switzerland plan works only in Switzerland, so in Konstanz, Lindau or Bregenz it gives no data on the local German or Austrian networks.

On the boats: the roaming trap on the water

Boats cross and circle the lake, and on the water a phone can connect to a German, Austrian or Swiss network, wherever the boat is heading. On an EU SIM, a Swiss network is roaming outside the EU, even on a trip between two German towns.

To avoid it, choose a German or Austrian network manually in your phone's mobile settings while one is in range; on a Switzerland plan, choose a Swiss one instead. With the Europe plan, a switch between the three countries' networks stays within the plan.

Liechtenstein, a short way up the Rhine

Liechtenstein lies a short way up the Rhine valley from the lake. It is in Roam Like at Home, so an EU SIM works there as at home, and the Europe plan covers it, but a Switzerland plan does not. Along the Rhine, a phone can also switch to a Swiss network across the river.

Which plan fits your trip

For a lake trip that touches the Swiss shore, the Telcomia Europe plan covers Germany, Austria, Switzerland and Liechtenstein on one eSIM, among 38 destinations. If you stay on the Swiss shore and elsewhere in Switzerland, a Switzerland plan is enough.

With an EU SIM you are already covered in Germany, Austria and Liechtenstein, so around the lake the gap is Switzerland. Standard plans are data only, with calls through apps such as WhatsApp; the plan details show the Activation line, which gives the start of the validity period, plus the duration, the data and whether you may share the connection.

Before you leave

Install the eSIM at home on Wi-Fi and set it as your line for mobile data.
Turn data roaming on for the eSIM and off for your home line.
Find manual network selection in your phone's settings before your first boat trip.
Check whether your home tariff includes Switzerland.
On board, check the network name before you use data.

Consular protection: one number around the lake

112 works in Germany, Austria and Switzerland; in Germany it reaches the fire service and ambulances, and 110 is the police.
In Austria, 133 is the police, 144 an ambulance and 122 the fire service.
In Switzerland and Liechtenstein, 117 is the police, 118 the fire service and 144 an ambulance.
Embassies are in Berlin and Vienna, and mostly in Bern for Switzerland; none are based in Liechtenstein, which the UK and the US cover from Bern. The Telcomia app shows which mission is responsible for you, with address and phone.
If you are an EU citizen and your country has no embassy or consulate in Switzerland, the embassy of any other EU country must help you on the same terms as its own nationals (Article 23 of the Treaty on the Functioning of the EU).
The app keeps key emergency phrases in German ready to show on screen.

Germany travel-safety page →

Switzerland travel-safety page →

Questions travellers ask about Lake Constance

Does EU roaming work on Lake Constance?

On German and Austrian networks, yes, for EU SIMs. Switzerland is outside Roam Like at Home, so on a Swiss network, wherever you are on or around the lake, your operator can charge roaming unless your tariff includes Switzerland.

Why did I get a roaming text on the ferry?

Out on the lake, your phone may have joined a Swiss network; on an EU SIM, this counts as roaming outside the EU. Choose a German or Austrian network manually while one is in range.

One eSIM for Germany, Austria and Switzerland?

Yes: the Europe plan covers all three on one eSIM, plus Liechtenstein, among 38 destinations. A Switzerland plan works only in Switzerland.

Which emergency number works around the lake?

112 works in Germany, Austria and Switzerland. The police numbers differ: 110 in Germany, 133 in Austria and 117 in Switzerland.

The short version

Around Lake Constance, Germany and Austria are inside EU roaming and Switzerland is not, and on the water a phone can join any of the three countries' networks. On an EU SIM, choose a German or Austrian network manually while one is in range, or use the Europe plan to cover all three on one eSIM.

See Europe plans →

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