You should receive a response pack with the claim. You have 14 days to respond. You should seek advice as soon as possible. You can:
do nothing, in which case it is likely the claimant can apply for Judgment in Default against you
pay the amount of the claim (in full or part)
admit the claim and ask for more time to pay (in full or part); and/or
dispute (defend) the claim (in full or part)
If the claim is defended, further information is usually provided by each of the parties, after which the case is allocated by a judge to one of three case management tracks (small claims track, fast track or multi track).