Before you start

Passport or national ID for verification
A German address, for postpaid contracts
A German bank account, for postpaid direct debit

Step-by-step

1
Buy a prepaid SIM and verify your identity
Available from supermarkets, phone shops and online. Activation requires identity verification — in shop with your passport, by video call, or through the Post's identification service.
In personWho: YouWeek 1
2
Do not attempt a postpaid contract in your first weeks
Contracts run a Schufa check and require a German bank account and registered address. With no credit history you will be declined or asked for a deposit.
OnlineWho: You
3
Order home internet the day you sign the lease
German broadband provisioning routinely takes several weeks and can require an engineer visit. Ordering on move-in day means a month of tethering.
OnlineWho: You
4
Ask specifically about listed-building constraints
Much of the Rheingauviertel, the Nordost quarter and the old town is protected stock. Fibre to the building does not mean fibre to your floor, because running new cable inside a listed structure needs the owner's cooperation and sometimes consent. Ask the landlord what is physically in the riser and what the last tenant measured.
In personWho: You
5
Check the address if you are in the left-bank districts
A Mainz-Kastel or Mainz-Kostheim address confuses provider systems, which sometimes route it to Rhineland-Palatinate infrastructure records. If an availability check gives an answer that does not match your neighbours', that is usually why — call rather than trusting the postcode checker.
OnlineWho: You
6
Know the cancellation rules
Since 1 December 2021, when the reformed Telekommunikationsgesetz took effect, a telecoms contract continuing past its minimum term can be cancelled at any point with one month's notice rather than auto-renewing for a full year. Check your specific terms — older contracts may still run on the old basis.
OnlineWho: You

Documents you’ll need

Passport or national ID for SIM registration
Meldebescheinigung, for postpaid contracts
German bank details, for direct debit
Schufa report, which some providers request

Things most newcomers don’t know

A well-preserved city is a slow city to wire.

Wiesbaden escaped the bombing that flattened most German cities of its size, which is why the centre is so handsome and why so much of it is under monument protection. That protection is exactly what makes running new cable through a stairwell a negotiation rather than an appointment. Ask what is in the building before you believe the availability map.

Source: community-reported

Even prepaid SIMs require identity verification in Germany.

Every SIM must be registered to an identified person, so a supermarket prepaid card still needs a passport check. Arriving expecting to buy an anonymous SIM off a shelf wastes an afternoon of your first week.

Source: Bundesnetzagentur

Home internet takes weeks, so order at lease signing.

German broadband provisioning routinely takes several weeks and can require an engineer visit. Order the day the lease is signed, using the future address.

Source: community-reported

The reformed telecoms law fixed a real contract trap, and it dates from 1 December 2021.

German telecom contracts historically rolled over for another full year if you missed the cancellation window. Since the Telekommunikationsmodernisierungsgesetz took effect on 1 December 2021, §56 TKG caps the initial term at 24 months and lets you cancel at any time with one month's notice thereafter.

Source: Bundesnetzagentur / §56 TKG