Compare Dual SIM Phones

People who want two phone numbers on a single device often use dual SIM to keep their personal and work lives separate. Travelers choose it so they don’t have to keep switching SIM cards. Exactly what you can do with it varies by device.

Which dual SIM phone is right for you?

Dual SIM doesn’t mean the same thing on every device. These factors determine what you can actually do with it:

• The type of dual SIM: determines whether both numbers are reachable at the same time.
• Two slots or one slot plus eSIM: with an eSIM, you have a second number without a physical card.
• A hybrid slot: either a second SIM card or a memory card—not both.
• VoLTE on both cards: determines whether your second number works.

Every device in this overview supports two numbers, and on most devices, you can set which number is used by default for outgoing calls for each contact. Your choice therefore depends on two questions: do both lines need to be available at the same time, and do you want to be able to continue using a memory card?

What types of dual SIM are available?

There are four variants, ranging from the simplest to the most comprehensive.

• Dual SIM Standby (DSS): you choose in advance which SIM card is active on the network; the other is deactivated. You switch between them via a menu, a process also known as “Dual SIM shift.”
• Dual SIM Dual Standby (DSDS): both SIM cards are active, but they share a single transceiver. If you receive a call on one SIM card, the other is unavailable at that moment.
• Dual SIM Dual VoLTE (DSDV): a DSDS device that keeps both SIM cards connected via VoLTE on 4G or 5G. This feature is found on many current devices.
• Dual SIM Active (DSA): two transceivers, so both lines remain available at the same time. Also known as Dual SIM Dual Active (DSDA). These devices are less common and drain the battery faster.

When using a second SIM card, check for VoLTE support. Calls made via VoLTE use the 4G or 5G network. Without VoLTE, calls fall back on older network technology, and 3G has been phased out in the Netherlands. Depending on your carrier and your device, the second number may therefore be difficult to reach or unreachable. Be sure to check with the manufacturer to see if the device supports VoLTE on both SIM cards.

Hybrid dual SIM

With a hybrid dual SIM, the slot for the second SIM card shares space with the memory card. This means you can either use a second number or expand your storage—but not both. For devices that come with plenty of built-in storage, this shouldn’t be a problem. If you’re considering a device with this type of slot, opt for ample built-in storage, since expanding it comes at the expense of your second SIM card. Many current devices no longer have a memory card slot; in that case, this trade-off doesn’t apply.

What SIM card sizes are available?

Physical SIM cards come in three sizes, from largest to smallest: miniSIM (2FF), microSIM (3FF), and nanoSIM (4FF). A dual-SIM phone doesn’t always accept two cards of the same size, so be sure to check this for each model. You can request a card in a different size from your carrier; many providers offer this service for free. We do not recommend using a SIM card adapter to make a smaller card fit a larger slot: it can damage the contact points or get stuck in the device, and such damage isn’t always covered by the warranty.

eSIM as a second number

An eSIM is a SIM card that’s built into the device. Instead of swapping out a physical card, you switch profiles: you activate a new plan using a code or an app from your carrier. For dual SIM, this is often the most convenient option, since you don’t have to give up a slot and can therefore continue to use your memory card. Many devices combine a single physical slot with an eSIM, and there are now also devices without a physical slot, in which case dual SIM means two eSIM profiles.