What type of bee is this?
Are these not Carpenter Bees rather than Bumblebees?
The brown dot in the middle of their golden color looks more like a Carpenter Bee to me.
A Bumblebee typically is brighter yellow and does not have these brown dots.
Bumblebee's also tend to have more than one yellow stripe, while Carpenter Bees just have one big yellow patch on their front half.
https://www.rescue.com/core/files/rescue/news/a48baab2138c7b489e613de951597d55.png
No, they are definitly Tree Bumblebees. https://www.bumblebeeconservation.org/learn-about-bumblebees/species-guide/tree-bumblebee/
The dot isn't really part of their inherent look, it's just where fur starts to rub away from bumping into and rubbing up against things over time. You can see that it's most pronounced on the left-most two and it's a phenomenon I've certainly observed in other species.
The UK (where OP has confirmed they are) has over 20 species of bumblebee and not all of them are black with yellow bands. Female red tail bumblebees, for example, are all black apart from their orange tail. There are five species of carder bumblebees that are various combinations of ginger, blonde and black/grey