For US passport holders, we need a visa to enter Vietnam. I had pre-arranged a visa on arrival, which meant that I had sent my passport, travel information, and a nominal fee ($9 per person) to a somewhat sketchy visa agent recommended to me by a friend (Vietnam Visa Pro, if you’re wondering). In return, I got a letter of approval.
After arriving at the Hanoi airport, I needed to get the actual visa prior to clearing immigration. This means that I needed to find the visa booth and hand over my passport, letter of approval, a completed entry and exit form, and a passport photo. After handing over my documents, I then went to the other side of the booth to wait for my visa to be processed. Once my name was called, I gave them $45 USD and got my passport with visa. It is VERY IMPORTANT that you have sufficient cash for the visa.
While I’ve heard that processing times at Ho Chi Minh (SGN) airport can be long, the whole process was done quite quickly at Hanoi airport. Granted, we were the only flight arriving at that time of night, so that perhaps helped mitigate delays. But I would readily do visa on arrival again.
I had tried to prebook a taxi from the airport through an online service, but no one was waiting for us when we exited immigration, so we went outside to haggle for a taxi. The first guy wanted $25 USD (~530,000 VND), which was way too much. The second guy wanted to use the meter initially, but it’s a very long ride (about an hour to Hanoi), and I didn’t want to give him any reason to take us for a ride, so I bargained for a fixed price of 350,000 VND (~$16 USD), which is what I had read was a fair flat rate to the city.
As for taking taxis in Hanoi, the advice that I heard was that Taxigroup and Mai Linh were the ONLY taxi operators that you should trust. This came directly from Vietnamese people. And to make sure that you generally don’t get ripped off on taxi rides from the airport, do your research BEFORE you land to understand what fair rates are. I personally use Wikitravel, but TripAdvisor, Flyertalk, and lots of other sites can be good sources of information.