Wireless power receiving apparatus 150 is retrofitted to a portable electrical device 100 to enable the device to receive power wirelessly. The apparatus comprises a power-receiving element 200 adapted to be attached to the device, e.g. by adhesive 201, and also being adapted to receive power wirelessly from a transmitter of power when the element and transmitter are in proximity with one another. One or more power connectors 203 are connected electrically to the power-receiving element and are adapted to be connected, when the apparatus is in use, to one or more corresponding power connectors 101 of the portable electrical device to deliver power received by the element to the device. The power-receiving element may be in the form of a sticker or may be carried by or incorporated in a replacement cover portion for the portable electrical device.