Compare dual SIM phones

A dual SIM phone holds two SIM profiles at the same time. For each number, you can decide whether it is used for calls, texts or mobile data. Today, phones almost always use “Dual SIM Dual Standby”: both numbers are reachable, but you can only make calls on one at a time. During a call on number 1, number 2 is usually not reachable unless you set up call forwarding.

Dual SIM can be implemented in different ways. Many Android devices have two nano-SIM slots; on some, the second slot is shared with the microSD card (hybrid slot) – so you have to choose between a second SIM and a memory card. Other devices combine a physical SIM with an eSIM, a built-in SIM that is loaded digitally. Most German providers now support eSIM.

Dual SIM is popular for separating work and private life, for a cheap data SIM with plenty of data alongside your calling plan, or for travel outside the EU, where a local SIM saves roaming charges. When buying, make sure both slots support the LTE and 5G frequencies used in Germany; on some imported devices, the second slot is limited to older networks.

You order an eSIM from your provider and usually receive a QR code that you scan in the mobile network settings. When switching devices, many providers let you transfer the eSIM directly; otherwise you request a new profile. Handy: several eSIM profiles can stay stored, even though usually only two are active at the same time.

Data-only eSIMs are practical for trips outside the EU: you buy a data package for your destination online and activate it before departure. Your German number remains reachable for calls and texts at the same time, without expensive roaming data charges.