Yes, your information is correct. British passport holders are required visa to enter Vietnam. In case you travel to Vietnam by air, applying Vietnam visa on arrival online is the best option thanks to its convenience and cheap price. Otherwise, if you enter Vietnam by land or by ship, you are suggested to obtain your visa at the nearest Vietnam Embassy/ Consulate.
Hopefully this information is helpful for you. Should you have any further concerns about Vietnam visa uk, please feel free to contact us at anytime.