Last reviewed 27 August 2026 · Based on current GOV.UK towing guidance and practical caravan-matching experience.
What does MTPLM mean?
Maximum Technically Permissible Laden Mass is the most the caravan is permitted to weigh when loaded for travel. Use the plated MTPLM—not an empty weight—when comparing a caravan with your car’s confirmed towing limit and the 85% matching guide.
What does MIRO mean?
Mass in Running Order is the manufacturer’s stated weight for the caravan in a defined running condition. The precise inclusions can vary by manufacturer and model year, so read the relevant handbook rather than assuming every brochure uses the same basis.
How is payload calculated?
The published user payload is broadly the difference between MTPLM and MIRO. It is the allowance available for items not already included in the MIRO definition.
- MTPLM − MIRO = published payload allowance
- Account for movers, batteries, air conditioning and dealer-fitted accessories
- Use a weighbridge to confirm the caravan’s actual travelling weight
Why the real loaded weight matters
A caravan may be below its MTPLM yet still be poorly loaded or exceed an axle, hitch or nose-weight limit. Keep heavy items low and close to the axle, secure everything and check the complete loaded outfit before travel.
Official sources and further checks
Rules and vehicle limits can change. Before towing, check GOV.UK towing-with-a-car guidance, GOV.UK towing weight and width limits and the documentation supplied by your vehicle, towbar and caravan manufacturers.