Since Oct 2013 a change to UK Insolvency Laws disallows an early discharge, that is before 12 months.
Therefore the earliest one can exit UK Bankruptcy is 1 year.
Payment Orders can last 3 years from petition.
Your bankruptcy will be automatically discharged after 12 months. Be aware that the Payment Order could last 3 yrs but can only be attached during the 12 month bankruptcy. You should be mindful that your income during bankruptcy should not exceed your reasonable monthly expenditure!!