How many years in prison can you get for sexual harrasment?

Firstly the definition of 'Sexual Assault' under British law is:

A person commits an offence is s/he intentionally sexually touches another person without their consent, and s/he does not reasonably believe they consent.

Section 3 of The Sexual Offences Act 2003

Its an either way offence which means it can be tried at either Magistrates Court (for less severe cases) and at Crown Court (more severe cases)

Magistrates Court (less severe cases) could imprison someone for up to 6 Months.

Crown Court (more severe cases) could imprison someone for up to 10 years.