I plan on hiring a car at BKK using a debit card. No problem there.

 

Checking online, most car hire companies require a credit card for security deposit at time of rental. I don't have one.

 

Does anyone know if they will accept a debit card or cash for the security deposit?

 

I think I will use an international brand such as Avis or Hertz. Does anyone recommend any particular company, either international or Thai.

Regards

Debit card is fine for this as long as you got balance for the deposit required. They normally don't take the money, it's just frozen until the bill is paid.