Hi Sarah, 

The Product Group codes are locked when the Product Group is created.  You are correct you can edit the description.  The work around would be to create new product groups with new codes (Making sure the settings are correct) and then move the relevant products into the new groups.

If you have a lot of products to change you could use the export / import function to make a bulk change quicker (more information on importing products can be found here: https://desktophelp.sage.co.uk/sage200/sage200standard/Content/Screens/Stock/ImportStockItems.htm.) 

Once all the products are assigned to the new groups you can delete the old ones.

As always make sure you have a backup before making any major changes to the data.

Many Thanks

Gordon

Thank you so much!! I have used the export and import function and it was successful.