According to the DfT there seems to be a misconception circulating about a requirement for “crash tested” beds or seats. This is not the case. The rules on MOT testing (annual test) are not changing"
Below is a link to the DfT information
sheet on the issue which was published in July 2012
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/8578/motor-caravans.pdf