The Older Drivers Forum warned entitlements would be “lost” unless motorists took action ahead of the cut-off.
They said: “When you renew your licence at 70, many of the other entitlements to drive vehicles of other categories will be lost unless you apply for them.
“If you use the standard D1 or online renewal procedure your C1 entitlement will be suspended and you will no longer be able to drive motorhomes between 3,500kg and 7,500kg until you have passed a medical.”
Elderly road users who don't want to apply for a C1 entitlement are not completely stuck though with experts suggesting there were motorhomes under the 3,500kg limit.
Wandahome commented: “The type of licence depends on two things - how old you are and the MAM (Maximum Authorised Mass) of the motorhome.
“The MAM is a sum totalling the motorhome’s weight plus the maximum load it can carry. Motorhomes with a MAM under 3,500kg can be driven on a standard category B driving licence.”
Applying to keep the C1 entitlement is not difficult and shouldn’t take more than a couple of minutes.
Those affected will have to simply fill out a simple application form with a doctor completing a medical assessment.
A post on the Older Drivers Forum added: “If you’re 70 or over (or soon will be) and are renewing your driving licence and want to keep the C1 on your licence you need to order and complete a D2 application form.
“Download a D4 medical examination report – this must be filled in by a doctor.”