In BUSY Accounitng Software,you can change goods to service in item tax category,you can follow these steps:
Step 1:Go to Administration menu,
Step 2:Select Masters,
Step 3:Click to Add Item,on clicking,If your item is a goods,a default tax category has been created for BUSY Accounitng Software.You can select the tax rate there as you want,then fill all the Details related to your product and save.
Step 4:If your item is a service,then you need create a new Tax category for service press f3 in cuser of tax category, mention name as service 18% or as you want to mention then select in type as service,mention tax rate then save, then your this item will consider as service item.