Here is what I discovered from my recent failed visa run to the Mae Sai border between northern Thailand and Myanmar.
The Green Bus from Chiang Mai does seem to be the best/most comfortable bus to take to the Mai Sae border, it cost 319 baht this week (March 5, 2016) for the first class bus, which has a bathroom. (I took the second class back to Chiang Mai a few days later, and that was only 160 baht, still comfortable, but no bathroom on board)…. The ride is about 5 hours with a few stops along the way, and they give you a snack and water, but the bus does not take you to the border aka the “Friendship Bridge,” it takes you to the station which is a few kilometers away.
When you get to the bus station it might be confusing if you haven’t done this before, so just remain calm, you’ll need to get a taxi, there will be a few pickup truck taxis in the parking lot and it’s about 15 baht from there. Just tell the driver that you want to go to the border, and be patient. I was told the border is supposed to close at 6 p.m. but that doesn’t seem to be the case, there was an officer on the Thai side of the border til much later letting people in, everyone but me it seemed, haha! (the immigration office does close at 6 pm).
So the issue that I’m facing, which I hope by writing this will help you avoid is– I arrived in Thailand in January and received a 30-day visa on arrival, I then went to an immigration office in February and had that extended for another 30 days, you can only do this extension once without flying out of the country; unless you have a multiple entry visa. So I arrived at the border hoping to walk over to Myanmar and get stamped for an additional 15 days until I fly to Laos next week, but the lady told me no, I need to go to the Thai immigration office, apply for a 7 day extension and then I can fly out; and because this was a Saturday, the day my visa expired, and the office was closed, I had to stay in MaeSai until the office opened on Monday, but from there it was pretty easy. Even though I had overstayed by two days, all I had to do was fill out the extension form and pay the 1900 baht fee and I received an additional 7 days so I can get out of the country legally.
** on another note, if you plan to stay in Mae Sai for a night, I suggest researching hotels/guest houses before going, but don’t book anything until you get there. The first night I stayed in the House Hotel. It’s literally a few hundred yards up the street to the left of the border and it was fine, nothing special, they wanted 300 baht, but I ended up paying 280. The internet was shaky but I didn’t see any bugs. The second night I stayed at Propha Place for 300 baht. I actually liked this place a lot better because of the young girl working there– she had such a welcoming attitude and in the evening she offered me dinner, which was definitely not included in the stay, but that just shows what a sweetheart she is– I can’t even explain how good it felt to have someone be nice to me after the somewhat stressful (but not unexpected) 48 hours I had in MaeSai. Anyways, hope my account helps someone else along the way… My best advice is– if you’re not sure whether you’re eligible to do a border run, just go to an immigration office and ask… save yourself the stress and money because after talking to several Thai and non-Thai people, it seems that the immigration policies, specifically those concerning travelers, are changing rapidly.