If you choose a digital TV service like Freeview, BT Vision or Top-up TV you will need to consider your aerial. If you have a satellite or cable service on all your TVs, you don't need an aerial.
Replacing your aerial
If you think you may need to replace your aerial, do not attempt to adjust it yourself. Look for an installer with the digital tick logo – this means they have been trained and security checked. Only Registered Digital Installers (RDIs) are permitted to use the digital tick logo. To find a RDI, visit http://www.rdi-lb.tv/
If you can’t find one, don’t worry. Look for someone with associate RDI, CAI Plus. See www.cai.org.uk. Alternatively, ask your local electrical retailer.