I just got an email from someone asking whether they could open an account in Thailand while they were on vacation in Thailand and staying in a hotel. The goal was to transfer small amounts of money to this account from time to time to build up the 800,000 Baht ballance that would be needed for the annual visa in a few years.
In my opinion an impossible undertaking. If you are on holiday in Thailand, you’ll usually don’t have a visa and with an address of a hotel you won’t get a registration certificate from the immigration office either.
Visa and an address in Thailand are the essential requirements to open a bank account at any bank in Thailand.
The different banks in Thailand have different demands when it comes to the requirements for foreigners. Some even want to see a work permit which a pensioner never has, for example.
Opening an Account with a Tourist Visa
I managed to open an account with the Bangkok Bank in 2014 only with a tourist visa, my passport and a registration certificate. Additionally required was only any kind of a second ID. In my case they accepted my German driver’s license or the national ID card (from Germany).
By this time I already lived in a rented house, however and thus had an address in Thailand.
Alternatives
If you only need the Thai account for the credit for the renewal of the annual visa, you should consider applying for a Non-Immigrant O-A Visa in your home country. With this type of visa, the capital must be in an account in the home country and not in Thailand.