To add to Jay's response - Contract Pricing in I/C will allow you to create the desired discounts.  You will need to have your invoice specification updated if you want this information printed on the customer-facing invoice.

Thank you, it took me a few minutes to find the Contract Pricing option. I am going to start testing today, thank you for the heads up about the customer facing invoices. I need to confirm that this discount will be reflected by item so when we run reports on sales the item sold price will include that discount.

when you do contract pricing you have 2 options: per category or per item.  when you do it per item, you also have to associate it to that customers set price list (i hate this, not sure why it's there).  so just be aware of this.  if you set it up and then change the customers price list, it will nullify your work.

Thank you, we thought about trying it per category since it is a flat discount across the board. But we will have to see if the sales reports show it the way we need. Would be nice if there was a option for all items, by item just means it will need to be updated every time we add new items and that is almost a weekly occurrence and we have 90 customers with special pricing. Hope to be using the import feature for most of this. 

Thank you, we thought about trying it per category since it is a flat discount across the board. But we will have to see if the sales reports show it the way we need. Would be nice if there was a option for all items, by item just means it will need to be updated every time we add new items and that is almost a weekly occurrence and we have 90 customers with special pricing. Hope to be using the import feature for most of this. 

if you have that type of need and applying to "all" items, then why not just create a different price list?  unless all 90 are going to have separate pricing from one another?  which just seems like more work than benefit.  

Sounds like you create a new price list for the customer which could include all items with the discount.  You can have as many price lists as you need.

Our top five customers all have different discounts and will be the primary use of the Contract Pricing option. Then we have a group of 88 that have one discount and we do have a price list for them, but we are looking at different options now that we are in Sage 300. We just upgraded from ACCPAC 5.3 and want to ensure we are using the best practice. Based on the last few comments the price list is the best option for those 88, thank you for the confirmation.