As Tod says thereās no official limit entering by visa exempt by air, BUT they will for sure start question you (ask for onward ticket, fund proof, accommodation booking etc), if you keep try entering on visa exempt for multiple times a year. Also it can depend on what passport you hold, prior entry history, which airport (some are more strict than others). Btw langborder runs are generally a ābig red flagā for any immigration officer, so donāt have to many of these in your entry history. At the end of the day thereās no fully correct answer, as it is totally up to the single immigration officer that you hand in your passport to š