Do I get a new 30-day entry to Thailand if I've already entered twice this year with a British passport?

As a British passport holder, you are generally granted a 30-day visa exemption upon arrival in Thailand. However, there are limitations on how many times you can enter Thailand by land; specifically, you are allowed only two land crossings per calendar year. Air crossings, on the other hand, are permitted without a set limit. Therefore, if you are returning by air after traveling to other countries, you should receive a new 30-day entry regardless of your previous visits earlier in the year.