The legal minimum is 20 days for the London office, 22 in Spain, at least that in Moscow. (This is in addition to public holidays.) Bumble probably offer a bit more.
In the UK and Spain, that's also the number you must use, I don't know about Russia. (In other words, if you've not used any days by December, you'll be taking all of December off. Or whenever your year wraps round.)
> You must take at least four weeks’ holiday a year, so only holiday on top of this can be carried over and then only if your employer gives you permission or if this is permitted by your contract of employment.
I once had a colleague who was given a letter along the lines of "you still haven't used enough holiday; unless you advise us of your preferred days, you will be on holiday from date X to Y".
In the UK and Spain, that's also the number you must use, I don't know about Russia. (In other words, if you've not used any days by December, you'll be taking all of December off. Or whenever your year wraps round.)