If try to raise a new purchase order with an existing supplier the page loads with the last purchase order information and I cannot raise a new purchase order

Hi Nikki,

Thanks for posting on Community!

This could be to do with the pre-fill form option in the account and settings, if you go to the Cog Wheel in the top right of your dashboard and select Account and Settings then select Advanced, under the option of Automation you will find 'Pre-fill forms with previously entered content' if you turn this off the old details shouldn't be displayed if the information is still there or you cannot edit let us know and we can look into this further.

Let us know if this helps.