Home > Broadband FAQ's > General Broadband FAQ's > What is a micro-filter?
A micro-filter is a special adaptor that you must use on your phone line, so that your telephone and ADSL signals are separated into two individual streams of data.
It is similar to a normal splitter used to connect multiple telephones to the same socket and are therefore sometimes also known as 'splitters' because of the way they 'split' the phone line into two data streams.
Since the purpose of a micro-filter is to separate voice data from computer data you must connect a micro-filter to each telephone socket in use in your house.
This means a micro-filter must be fitted to each telephone socket to which another device, such as an additional telephone, a fax, or satellite television's digibox, is fitted, in order to separate 'normal' telephone use from ADSL use.
If you have a dedicated line, used exclusively for ADSL and nothing else, then you do not need to use a micro-filter.
You do not need to fit a micro-filter to a telephone socket which is not in use, for example, a socket in a spare bedroom, although you must be aware that if you subsequently decide to use the socket, it will require a micro-filter.
Yes. If you prefer, you can obtain a replacement Master socket cover. You may need an engineer to fit this for you.
Micro-filters are usually, though not always, supplied with your ADSL modem, and are also easily purchased from a variety of outlets. The price is around £5 - £10.