There is no minimum capitalisation required, however, for each foreign employee the company is required to register with capitalisation of 2,000,000 THB to be qualified for the quota of one work permit. This requirement is lessen to be 1,000,000 THB if foreign employee is married to Thai national.
For example, 1 foreign employee = 2,000,000 THB, 2 foreign employees = 4,000,000 THB and so on.
However this does not mean that you need to deposit this amount of money to start, it is the limited liability of your Thai limited company.