For the past few years, Thailand has enacted and enforced a policy whereby foreign registered motorcycles have to have a "Transit Permit" to enter and cross the Country.
This has to be arranged 30 days ahead, using a Thai travel agency to apply to the Land Transport office, arrange the third party insurance, and provide a local support vehicle/guide.
Having ridden from the UK to Thailand, I struck a relationship up with a local agent who can arrange these permits, while allowing me to provide the necessary "support". This has worked well on two previous occasions.
In reality, this means I provide the necessary itinerary for the permit, meet riders at the border, then shadow for some/all of the way in a pick-up truck with a Thai guide.
Of course, I'm happy to share my experience of the country and can suggest the best riding routes through the Kingdom, and book hotels if required.
Many riders will want to exit into Malaysia. However, should you end the trip here and need packing & shipping services back to your home Country, I will provide details of a Bangkok based agent I have used before and trust. In this case, I work with them to ensure your bike gets dropped off at the correct place, giving you time to explore, but without the risk of going over the temporary import conditions.
If your trip planning involves Laos and China, I can recommend Companies I have experience with, although my actual involvement is only for Thailand.
If anyone requires more details, please PM me.

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Hi Russ,
We are an Italian couple planning to cross Malaysia into Thailand with our car to Sadao or Padang Besar border. Do you have any information about all the paperworks required for Thailand? Also, can you recommend any tour agency for Thailand?
hope to hear from you soon
Thank you
Silvia&Davide

Hi,
The official notice is
https://www.mots.go.th/mots_en57/dow...hicle(ENG).pdf
I can not recommend any particular agency for your crossing but you might try a Google search. You will notice that the permit requires a guide to travel with you in a Thai registered vehicle. Many agencies are strict about this, although the one I work with lets me bend the rules in how the tour is "supported".
However, what is important is that they are with me at the border to ensure a smooth entry and allow customs to witness the support vehicle as is sometimes asked for.
When meeting people in the North of Thailand, the support costs are far less than to travel in a truck to Sadao/Padang just to get you in.
Hope this helps, but if anything changes, please get back to me.

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