Но теперь:
Q: Why do rental car companies ask for a credit card?
A: Rental companies need to know that their renters are credit-worthy, to minimize vehicle damage and losses. Credit cards and valid drivers' licenses usually provide the only information we have about our renters.
Q: Can I use a debit card?
A: No, this procedure is not yet effective in Thailand.
http://www.budget.co.th/tips_faq.aspx#Pap2
И в реальности так и есть
Более забронировать по дебетовой карте невозможно.