Can you extend your 60-day stay on a METV and are you guaranteed entry each time?

2) The METV online application states "you need to prove that you have a genuine reason to visit Thailand on a regular basis." Does this mean you may be granted the METV, but then are not guaranteed to get a 60 day stay each time you re-enter?

you need to show them WHY you need an METV, so make a round trip booking 60 days from the date you're arriving in thailand to singapore for a few days and use that as the "proof" you need a METV.

Most consulates IF you pay the 200 USD but don't get the METV issued will NOT refund you the difference when they issue you a 40 USD single entry visa

Are you NOW Thailand?

You asked a similar question recently...with answers.

Question about METV: Do you get 60 days when you re-enter by land? Or do you have to re-enter at an airport to get the 60 days?

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1) While many immigration offices allow you to apply for a 30 days tourism extension for every entry on METV, we can NOT guarantee ALL immigration offices allow it. You better check with an immigration office that serves the address you are staying at the last of your itinerary in advance.

2) Regardless Multiple Entry or Single Entry, the visa itself doesn't assure you to be approved for your entry to Thailand. A visa assures how many days you would be permitted IF you are approved to enter Thailand. Thus, your entry into Thailand once on METV doesn't assure your next entry to Thailand on the same METV either.