Vietnam government changed "old visa exemption rule" to "new visa exemption rule" (have to wait 30 days passing for re-entering into Vietnam with no visa) several years ago.
Before Vietnam government changed the rule as above, i repeated to exit & re-enter into 3 countries (Vietnam & Laos & China) in a long trip to 3 countries getting a new stamp for "15 days staying with no visa"=15 + 15 + --- . But now it's becoming impossible for me to re-enter into Vietnam soon just after exiting Vietnam under new visa exemption rule.
But other 2 countries(Laos & China) have not changed visa exemption rule yet, at least, till today so if you exit Laos and enter into Vietnam then re-enter into Laos , you can get a new stamp of 15 days staying with no visa or 30 days staying with new visa at Lao border(VOA).
Or do I have to wait a certain amount of time to re-enter Laos?
---in case you go to Vietnam, i reccommend you to stay(or trtavel ) in Vietnam for several days before returning to Laos for reducing a conciousness of waste of money .
"Which border crossing point is the best for you" depends on your travel schedule in both countries and where you are staying in Laos now.
①Pang Hok(Laos)/Tay Trang(VN) border---between Muang Khua and Dien Bien Phu(5 hours only between 2 by direct bus)
②Nam Phao/Cao Treo(VN) border---between Vientiane and Ha Noi (distance between 2 is very far)
③Nam Xoi/Na Meo border---between Sam Neua and Thanh Hoa, if you can stay at Viengxai village near Sam Neua, distance from Vieng Xai village to Lao border(Nam Xoi) is 54km only/ Sam Neua to Lao border is 82km.
④Nam Khan/Nam Can(VN) border---between Luang Prabang/Phonsavan and inh (distance between Phonsavan and Lao border is very far)
⑤Na Phao/Cha Lo(VN) border---Thakhek(in southern Laos) and Dong Hoi near Hue(direct bus via Na Phao/Cha Lo border is not daily service)
⑥Densavanh/Lao Bao border---between Vientiane・Savannakhet and Hue(distance between VTE and Lao border is very far)
⑦Phou Keau/Bo Y border ---between Pakse・Attapeau(119km from Attapeau to Lao border) and Ngoc Hoi(19km from Bo Y border)・Kon Tum(60km from Bo Y border） in Central highlands/there are several direct buses between Laos and Vietnam
I think "①(=in case you are staying at northgern Laos now) or ⑦(=in case you are staying at southern Laos now) + staying at Vietnam side for several days is better.
---①＆⑦ are easy to access to Lao border and border crossing process is smooth and finding a transport for returning to Laos is not so difficult(you need to check it at Vietnam side asking to Vietnamese for yourself if you choose this route)
If Garman tourists can be applied "visa exemption rule" for entering into Thailand and you are staying at Pakse or Vietntiane now , "Vientiane/Nong Khai border" from Vientiane or "Vang Tao(Laos)/Chong Mek(Thai)" border from Pakse spending half day only is another better option.
---walking around VN immigration building(house) or Thai Immigration building(house) for few mins only or take a coffee break only then return to Laos is OK.
(I'm not good at English so maybe difficult to read and understand my replying ut all my comments are based on my actual travelings and experiences)
(by jp_geckozy)
