21/22 + bank hols. Increases after 3/5 years service or something like that. But up to 2 days flexitime per month allowed if you've worked unpaid overtime. can carry over up to 5 per year.
My first job was 23, increasing by 1 for each year of service up to a max of 5. On top of that, we had a flexible benefits package where you could buy/sell hols, up to 5. So, we could have 33 + bank hols, which was amazing. Could also carry over up to 5 per year.
Not come across another engineering consulting company that does the same sadly.