There is no set rule, ot depends on the Company. Some will allow a certain period of compassionate leave and pay you for it (usually about 3 days) and some don't pay. There is no entitlement to paid leave.
Most companies will give compassionate leave for the day of the funeral - if you have no holiday entitlement left. There is no obligation for your employer to give you any paid time off. Many small employers just cannot afford it anyway.
My husbands dad died and he had to get a sick note from the doc to get 2 weeks sick pay to allow him time off.
My gran died who was like my mum, and my company gave me 4 days compassionate leave on full pay, so it really depends on the company, by law they dont have to give u time off. If you feel you need it tho, and they wont give u time off, then get a sick note, but in my hubbys case he just got stat sick pay xx