The maximum amount of statutory paid holiday you can be entitled to is 28 days. This applies even if you work more than five days a week.
Your contract of employment may give you the right to take more than the statutory amount of paid holiday. However, it cannot give you less. For example, if your contract of employment says you can only take 10 days' paid holiday a year and you work five days a week, you will still be entitled to take 28 days' paid holiday.