You mention SE-Asia and want to know rules about buying and owning a bike there as a foreigner.
First of all you have to know that SE-Asia is not a country - its several countries. Actually its 11 different countries in SE-Asia and all have different rules according to your questsion. So as you might understand there is no simple answer to this….
I will try to mention what I know about this….
1. Thailand - yes a foreigner can buy and own a motorbike in Thailand. The most important is to get a sertificate of recidency as you will need this document to register a bike in your name. This document can be a PITA to get sometimes but I have heard if you buy a brand new bike the dealer sometimes can help with that.
Then you will have to wait for plates. This can in some provinces take several months, in other provinces just a few days. You just have to ask locally to get info about this. You cannot cross international borders before you get plates on the bike. And from what I have heard you shouldnt take the bike outside the province its registrated in before you get the plates - although I dont think this is very important (unless your in an accident…)
You need also to pay a yearly tax and basic insurance to get it plated and legal. If a bike is 5 years old or more it needs to get a yearly inspection.
A thai plated bike can easily be taken into Laos, Cambodia and Malaysia. Vietnam demands a guide and permits for a thai plated bike which is expensive. A very few thai plated bikes have managed to get into Vietnam without guide and permits - but its definetively not the rule. Myanmar demands guides and permits for all foreign bikes. Indonesia demands a Carnet for foreign bikes and I dont know where to get a Carnet for a thai plated bike.
And this is only the rules for Thailand - and I do own a bike in Thailand so I know a bit about it…
2. Laos - I dont know the rules for
3. Myanmar - my guess is if you have a recidency you will be able to buy a bike there - if not its not possible to do it legally.
And remember any foreign vehicle travelling in Myanmar will need guides and permits…
4. Vietnam - heaps of backpackers buy cheap motos in Vietnam and also cross the borders to Laos and Cambodia with them - so that should definetivwly be possible to own a bike there. From my understanding you simple get the ownership document with you when you buy the bike and as such there isnt a problem owning a bike there. I have no personal experience about this however….
Crossing borders to Laos and Cambodia isnt any problem with a vietnam plated bike - but for Thailand a vietnamese plated bike need guides and permits.
5. Cambodia - I really dont know
6. Malaysia - it is possible to buy a motorbike in Malaysia as a foreigner. I have read detailed reports about it, just dont remember where.
7. Indonesia - from my understanding its possible the same way its possible in Vietnam. You buy a bike and by that you also get the ownership document of the bike. And as such you can ride it where you want. Dont know about bordercrossings with it, but then again Indonesia dont have many landborders with other countries, only East Timor and Malaysia on the Borneo island (called Kalimantan in Indonesia)
8. East Timor - I have no idea
9. Singapore - I have no idea
10. Brunei - I have no idea
11. The Philippines - I am not sure if a foreigner on a tourist visa can buy and register a bike there. Expats with long term visas can definetively buy a bike there - but the registration process can be very very time consuming. I have read several complaints about this on different forums…
Hopefully others with more detailed info about these countries can chime in and share info….
To sum it up - SE-Asia are 11 different countries - thus 11 different set of rules. And add to this that in many of these countries law enforcement isnt always consistant - to speak mildly - it can be a challenge to buy a vehicle and travel with it legally. As always - expect the unexpected ans smile…