Taxis are the most comfortable way of getting around, and very modest in price compared to other major cities in the world. Rates fluctuate over time depending on the cost of fuel, but in late 2010 with oil in the US$80s per barrel on world markets, honest Ho Chi Minh City taxis were charging in the range of 12,000 to 13,000 dong per kilometre. Taxis are numerous and it's usually not hard to flag one down anywhere in the city centre from early morning until about 1:00 am, though finding one in the rain or during workday rush hours can be difficult.
Taxi rates are not regulated by the city government, so each company sets its own fare structure which changes from time to time. You cannot choose a taxi at random and expect a standard fare; it is a caveat emptor market with a fringe of dishonest operators which prey on foreigners in particular. Fortunately, the market is fairly competitive and 80% of taxis are operated by reasonably honest companies with similar rates. The market of these companies is more than 90% local, so their policies are designed to win the trust of Ho Chi Minh City residents. For a list of taxi companies reported to be reliable, see "Taxi" in the "Getting to the city centre" section above.
Dishonest taxi drivers may start driving without starting their meters, then demand a high fare or try to negotiate for a fixed price at a location where it's difficult for you to hire another cab. Therefore, make sure your taxi driver agrees to use the meter, and turns it on before you get in. (As mentioned above, some taxi companies such as Mai Linh and Vinasun have meters in their taxis that start automatically once the vehicle starts moving.)
Drivers generally speak limited English and do not speak any other foreign languages, so it's wise to write the name and address of your destination, preferably in Vietnamese, to show the taxi driver. Your hotel staff can assist. It also helps to carry one of your hotel's business cards so you can return to the hotel without too much fuss. Carry small change and bills for paying fares, since drivers are often short of change. Taxi models in service are mostly Toyota Vios sedans (up to four passengers) and Toyota Innova minivans (up to six passengers), which are assembled in Vietnam and inexpensive to buy. Fares are almost always the same regardless of car model, though anything larger than an Innova generally costs more. Some older cars might lack working air-conditioners.
Taxi drivers are likely to drive too fast when given the chance. Ho Chi Minh City has a unique traffic pattern in which cars and buses drive in the centre lanes on two-way streets, or the left lanes on one-way streets, while the outside or right lanes are reserved for motorcycles. During weekday rush hours, the car lanes often barely move for blocks on end, while the motorcycle lanes move a bit faster. Taxi drivers vary in their tendency to squeeze into the motorcycle lane and jump ahead of other cars. In theory, they can be fined for doing so. Rush-hour traffic in the city has become so bad that you might consider just planning not to go anywhere between the hours of 7:00 and 8:30 am, and 4:30 to 6:00 pm.
Taxi rates are very reasonable in Ho Chi Minh City as long as you use a reputable company and the meter is used. Mai Linh (mostly white with green lettering, though sometimes green or silver) Tel. +126.96.36.199.38.38 (or 08.38.38.38.38 if dialling from a local telephone) and Vinasun (white with green and red lettering) Tel. +188.8.131.52.27.27 have the largest fleets in the city and are generally honest and reliable, with meters that start automatically after the taxis have moved about five metres. At the airport, Mai Linh taxi wardens wear green shirts with green ties, and Vinasun wardens dark green shirts with maroon ties. To find the Vinasun wardens, you need to walk to the end (far left) of the taxi stand. These wardens can help to radio taxis for you and will give you a ticket that has the taxi number in case you have issues. However even the drivers of these companies may try.
Be cautious of taxis from dubious companies with names that resemble the reputable companies mentioned above. Some of these include Mei Linh or Mai Lin instead of Mai Linh, and Vinamet, Vinason or Vinasum instead of Vinasun. It has been reported that such companies charge outrageous fares to unsuspecting passengers, sometimes by using meters that run faster or by manually increasing the fare when passengers are not looking. There have also been instances of taxi drivers from such companies driving off with passengers' belongings still in the boot.
Other taxi companies with smaller fleets that have been reported as reliable include Festive Taxi, Happy Taxi, Hoang Long (yellow top and green sides), Petro Vietnam (silver and green), Petrolimex (white, blue and orange), Savico (blue), Taxi Future (silver with orange lettering) and Vinataxi (yellow). Historically, Savico and Vinataxi have been the cheapest by about 10%; while Hoang Long and Taxi Future are perhaps 10% higher than the average.
Taxis that some travellers have suggested avoiding include the following:
Saigon Air Taxi (mostly white Isuzu SUVs). Their metered rates are reportedly competitive, though the company was started with the purpose of charging high prices to visitors for airport trips. With other taxis abundant, there is no reason to take the risk of an overcharge.
Saigon Tourist (mostly silver with pink trim and a flower emblem). Their meter rates are reportedly competitive if they agree to use the meter, but they are notorious for refusing when passengers are foreigners, especially when picked up anywhere near a hotel. Drivers might require payment in US dollars instead of in dong, or quote fixed prices that are double the normal metered rate or more. Saigon Tourist taxis cluster around some of the larger, upscale hotels in the city centre such as the Caravelle, New World, Park Hyatt and Sheraton, and hotel staff won't hesitate to put you into one of these tourist trap taxis unless you specifically ask for a different taxi company. The Sheraton only allows Saigon Tourist to pick up at its door unless you specifically ask the bellman for a different company.
Other tips for avoiding scams
Avoid buying taxi coupons from dubious companies. Some dubious taxi companies that overcharge have booths in the airport terminal buildings. Only buy taxi coupons from reliable companies such as those named above.
Avoid taxi touts. Watch out for taxi touts who dress in uniforms and brandish laminated "fixed price" cards at 4,400,000 dong per car to the city hotels. They will be prepared to drop the price to 2,600,000 dong but it is still a rip-off. Ignore them, and stick to metered taxis or reliable taxi companies.
Do not ask taxi drivers to suggest hotels. Taxi drivers earn commissions by taking customers to certain hotels, so be explicit about exactly which hotel you want to be taken to. Some taxi drivers have been known to trick visitors into staying at hotels which they recommend by informing them that the hotels the visitors have asked to be taken to have "no vacancies" due to some big event in town or have "burned down recently".
Know what the journey should cost. Some drivers, even from reputable companies with the meter running, will try to take advantage of currency confusion - for example, if the meter reads 40.0 for 10 minute journey, they will claim you owe 400,000 dong when in fact you owe only 40,000. Be sure to have some smaller bills before entering the taxi. Taxi drivers will not usually make change. The amount shown on the taxi meter needs to be multiplied by 1,000. So, 50 showing on the meter will be 50,000 Dong, about USD $2.35. It is helpful to pay attention to the meter and plan ahead so that you are not rushed to pay as you leave the taxi and collect your luggage.
Drivers may ask for $3-5 USD to 'pay for airport parking'. First, this is a grossly inflated price as the real surcharge is about 50c, second, it's included in your voucher fare. Just keep saying "paid with voucher" each time the driver insists.