Is it impolite to ask for halal food when traveling to and in Thailand?

I have a very simple rule:

If you have to ask, it is not halal. If it was halal you would clearly know it by virtue of signage in any non Muslim country.

Halal food in non Muslim countries is a minority speciality and there’s no point in someone serving halal food without promoting it clearly, in such places.

So if you haven’t seen the sign on or in a shop, don’t even bother asking. Assume it is not halal. This works for me almost everywhere.

Since your question was primarily about Thailand, look for this sign on any food outlet you're interested in. If you don't see that or a similar looking sign, move on. It may not be impolite to still ask, but it doesn't serve your purpose and it wastes your and theirs time.

Source

So follow 2 steps:

1. Google Halal food near me
2. Go to any possible recommendations and see if they say so.

All of the commentators saying It is OK to just ask and accept the word that most of our products are halal unfortunately do not comprehend the concept of halal as a practicing Muslim would take it.

Even vegetables, cooked in pork fat, or with one millimeter of alcohol can be deemed Not Halal.

Even Fish or Chips, fried in the same oil that Pork was fried in, is considered Not Halal by most schools of Islam.

If you really are serious about it, look for the government sanctioned sign!

For long distance flights, ordering a special diet meal is a well established procedure. When you have bought your flight tickets, just contact the airline customer service and ask for a halal meal (usually needs to be done at least a few days before the flight). There is nothing impolite about this.

If you forgot to pre-order your special meal, or you for some reason needed to change your flight plans last minute, you can explain this to the flight attendant and they will usually do what they can to accommodate you. As long as you are humble about it, this will not be seen as impolite.

For short distance flights, they normally just serve lighter snacks, and it is not possible to make a special order. You can always ask the flight attendant about the snacks served and if you are not confident that they are halal you can politely decline. There is nothing impolite about this.

It's definitely not impolite to ask. In some countries (but not in Thailand I believe) it is considered impolite to say "no" so some people would think it is polite to lie and answer "yes" rather than "I don't know" or "no, it isn't halal", so you'd need to be careful.

But in many countries, including Thailand, sellers know that they have more potential customers if they sell halal food, so you will have places selling food marked as "halal".

I have been told that if you are told that food is halal, when it's not obvious whether it is or not (like you can't really see whether a steak is halal or not), and you are lied to, then you are fine from a religious point of view. The same person (who is not a very strict muslim but knows the rules) told me that he can taste the difference between meet that was slaughtered in a halal way or not. But that is obviously entirely up to you.

And obviously you may have problems. The restaurant owner and the chef might not know if their beef is halal and tell you - the rules about being lied to don't mean you can eat beef if it is not known to be halal, only if the chef lied to you and claimed it was halal. If you like fish, you should be fine.