Broadband - BT line -splitters

[Pinotage]

Do I need splitters on every phone socket - or only on ones where I have phones or the modem plugged in?

[foulecamp]

If you mean filters, then you need one on every phone socket - get spares, because it can take a couple of goes to get them to work properly.

[Ralph]

You need a microfilter on any piece of telecom equipment, including Sky boxes, connected to the phone line. If you don't have something connected to an outlet, then you don't need to filter it. If you have multiple items on the one socket, just put the filter first and you'll be fine.