This lets you use a local SIM card while traveling without losing access to your home number, or it lets you keep your personal and professional affairs apart. Dual standby is another feature of some dual SIM devices that allows both SIM cards toslots uk be active and receive calls & messages at the same time. You can quickly determine which line is being used when you receive a call or message because your device will display the number that the communication is coming from. This guarantees that you never miss a crucial call or message and makes managing incoming communications simple. You can stay connected on both numbers with dual SIM technology, eliminating the need to carry around multiple devices or swap out SIM cards frequently.