This depends on the assistance provider - you will need to check your policy wording.
The annual UK breakdown policy with assistance provider National Breakdown includes recovery of your caravan following the breakdown of your vehicle.
If your vehicle suffers a breakdown and your caravan/trailer is attached, providing the caravan/trailer is fitted with a standard towing hitch and does not exceed 7 metres/23 feet in length (not including the length of the A-frame and hitch), your caravan/trailer will be recovered with your vehicle at no extra cost.
Please note that if your caravan breaks down or you are involved in a traffic accident, this policy will not respond.
The UK breakdown policy with Emergency Assist Ltd will recover your caravan or trailer to the same location as your vehicle following a mechanical breakdown of the vehicle named on your policy. The caravan or trailer will need to be under the following limits - gross weight: 3.5 tonnes, length: 7.0 metres (23 feet) excluding draw bar and coupling, width: 2.44 metres (8 feet). This policy will not respond if you are involved in an accident or if your caravan breaks down.
Allianz Global Assistance offer a UK breakdown policy which will also recover your caravan or trailer you are towing providing it does not exceed 3500kg in weight (including load), 5.5 metres in length, 3.0 metres in height or 2.3 metres in width - these limits include any caravan or trailer that you are towing. The policy will not respond if the caravan breaks down. This policy will also recover the caravan or trailer following a road traffic accident.