Routing data transmissions in dual-band devices is described. In an example, a system can determine, based at least in part on capabilities information associated with a device, two or more networks that are available to the device. The two or more networks can include at least a fourth generation (4G) network and a fifth generation (5G) network. The device can be anchored in a first network of the two or more networks. The system can determine first characteristic(s) associated with the first network and second characteristic(s) associated with a second network of the two or more networks. Based at least in part on the first characteristic(s) and the second characteristic(s), the device can determine to transmit data via the second network instead of the first network and can transmit the data via the second network. The system can be associated with a service provider or the device.