As some of you may be aware, the visa laws in Vietnam have been changed since Jan 1st 2015
Under the new laws, those who currently hold C category (tourist) and B category (business) visas must now leave the country before the visa's expiry and return on the new visa categories. The C and B visas have now been abolished and are being replaced by newer categories.
To receive business visas in the future, expats must have supporting documentation proving that they have either a work permit for a company in Vietnam, or that they are involved in a company here (as an investor or owner).
If you don't have these documents then you must return on the new tourist visa category (valid for 3 months).
What this means is that border runs are likely to become more frequent as the tourist visa will not be allowed to be extended multiple times as you would have done in 2014 with the B3 visa.
If anyone needs further info, don't hesitate to ask or PM me
Colm