From Noi Bai airport to Hanoi Old Quarter, there are taxis that run at fixed rates waiting outside of the arrival hall. It costs between 345,000 - 375,000 VND depending on the type of taxi you get (or $16-18). Three official taxi brands for airport routes are: Noi Bai Taxi, Viet Thanh Taxi and Dai Nam Taxi, you can also take a look at our Guide to taking taxi at Noi Bai airport here.
In any case, do not go by the meter because the rate will be much higher than the fixed rate. You also need not pay any toll fees. Tips are not required though if the driver is really nice you can also give tips.
We offer airport pick up from Noi Bai Airport to your selected location in Hanoi: classic service for only $15 and premium car service for $18. Contact us for booking or view Transfer page for further option.