Until they end up in hospital or cop shop and then house owner is in the deep stuff - law is fairly clear on house owner/landlord responsibility - always register my daughter or friends when they stay I don’t need to get on the wrong side of immig not worth it
Hard to know immig officers are certainly more vigilant now, I have a few friends who have been challenged for the first time and they are just visiting 2 or three times a year from NZ
You run the risk of being pulled, once a pattern of border hops appear, additionally Thailand is looking at implementing Electronic Travel Authorisations (ETA) next year, similar to Sin and Malaysia this will allow them to screen out folks gaming the system before they even arrive. Better to break the pattern by spending time between both countries, not a long flight, otherwise crack away until you get stopped….and have a plan B
except it’s not being driven by Thailand but the OECD and the US especially, they want to remove tax bolt holes like thailand - I would rather they follow Dubai, and tax consumption
If you are here more than 180 days in a calendar year you become tax resident, and remittances during that tax year are subject to Thai income tax effective 2024 so our first returns are due by end Mar 2025 - allowances are generous and if you from a country that has a DTA unlikely you will pay any tax here. If you can prove income is pre 2024 then large amounts for property or car purchase are also exempt. An accountant will handle tax return from B8k upwards.
Try opening an account in most western countries without residence, virtually impossible now, had to close my accounts in South Africa, Dubai and HK in last 5 years due to non residency, I keep my UK for now as I have a property there , still - that will be difficult when I sell up it’s a worldwide attempt to reduce money laundering.