Sky sport in old SD Box

Help required from sky knowledgable folk! My Dad, a UK Sky sport subscriber is with us for 2 months, he has bought his card with him, but it doesn't work in our old SD box, I understand that to receive premium sky services you need to pair the box and card, is this possible with an old box like ours? Box is approx 15 years old and registered in Scotland, don't want to try pairing and bugger up his card!