I put off replacing my driver's license for a long time because I didn't want to deal with the photo requirements. I thought I would upload a decent photo, and everything would be fine. But after reading the requirements, I realized everything is strict: You need a neutral background, natural light, no shadows on the face, and a certain head size. In general, without preparation, you can easily get rejected.
At first, I tried to take the photo myself: I stood near a white wall, put my phone on a tripod, and turned on the timer. It would seem that everything is simple, but the light is uneven, or the background is not perfectly white. After several unsuccessful attempts, I decided not to risk it and to look for a service that would help to adjust the photo to all the requirements. In the end,d, I found a handy online tool that immediately checks the photo, removes the background,d and adapts the image to DVLA standards. You can check it out here: https://photogov.net/documents/gb-driving-photo/.
Everything was easier than I thought: I uploaded a photo and got a ready-made version, which was accepted without problems. If anyone else will also take a picture, I advise you to study the requirements in advance and not rely on a random shot - it will save time and nerves.