Intro:

Having a German phone number is essential for banking, university logins, deliveries, and staying in touch. This guide explains the differences between prepaid SIM cards and mobile contracts, what they cost in 2025/2026, and how to avoid hidden fees as a new international student.

1. Why you need a German phone number

• Many services in Germany use SMS or app codes (TAN) for two‑factor authentication, especially online banking and government portals.
• Landlords, employers, and offices often prefer German numbers when they contact you for appointments or documents.
• Local calls and data are usually much cheaper with a German SIM than with international roaming.

2. Prepaid SIM vs. mobile contract: the basics

• Prepaid SIM: You pay in advance, can top up when needed, and usually have no long‑term commitment.
• Mobile contract (Vertrag): Fixed monthly payments for 12–24 months, often with more data and sometimes a phone included.
• For most new international students, a prepaid SIM is the safest and most flexible option for the first months.

3. Prepaid SIM cards: advantages and typical costs

• Prepaid SIMs are easy to buy in supermarkets, electronics stores, kiosks, and online; you usually only need your passport for activation.
• Common prepaid bundles cost roughly 8–20 EUR per 4 weeks for a mix of data, calls, and texts, depending on volume and network quality.
• You can stop using the SIM at any time without cancellation periods, which is ideal if you are unsure how long you will stay.

4. Mobile contracts: when are they useful?

• Contracts can be attractive if you stay in Germany for several years, use a lot of data, or want a new smartphone included.
• They usually run 12 or 24 months and require a German address, regular income or proof of funds, and often a SCHUFA credit check.
• Ending a contract early is usually difficult and expensive, so they are not ideal if your plans are uncertain.

5. Registration and identification (Know‑Your‑Customer)

• German law requires identification when activating SIM cards; you cannot use anonymous prepaid SIMs.
• For online purchases, you typically complete a video identification with your passport; in stores, the staff scans your ID.
• Always enter your data exactly as in your passport and registration certificate to avoid activation problems.

6. Choosing a provider and network

• There are three main networks and many low‑cost brands that use them; coverage and speed can differ between urban and rural areas.
• Ask other students in your city which providers work well on campus, in dorms, and in your neighbourhood.
• For prepaid, focus on data volume, hotspot options, and whether EU roaming is included if you plan to travel.

7. Avoiding hidden costs and traps

• Be careful with contracts that advertise low prices but add extra fees for activation, paper bills, or small print services.
• Disable paid add‑ons you do not need, such as premium numbers, third‑party subscriptions, or extra voicemail services.
• Monitor your usage in the provider’s app to avoid running out of data or accidentally using expensive extra data.

8. Using your foreign SIM together with a German SIM

• If your current phone supports dual SIM or eSIM, you can keep your home number active for banking or family while using a German SIM for data and local calls.
• Turn off mobile data roaming on your foreign SIM to avoid very high roaming charges.
• Tell family and friends to use internet messaging apps when possible instead of international calls.

9. What to do when you move or leave Germany

• For prepaid cards, you can simply stop topping up; after a certain period of inactivity, the number is usually deactivated.
• For contracts, you must cancel in writing within the notice period (often one to three months before the end of the term).
• Always keep proof of cancellation and any final bills, especially if you plan to return to Germany later.

10. Key points to remember

• Start with a flexible prepaid SIM in your first weeks; upgrade to a contract only if you are sure you will stay longer and need more data.
• Compare offers by data volume, EU roaming, and real costs, not just by advertised “from” prices.
• Keep your number and login details safe, and use the provider’s app to control costs and avoid unwanted charges.