QB Issue Resolution:

the IRS is specific

you do not enter a sales discount separately, you enter the actual amount paid, see this
http://onsale-apparel.com/Rustler/tag/irs-inventory

a terms discount for paying early, the offset account is income

Resolution for Issue 'How do I record discounts from vendors gross as a part of cost of goods sold? I could do this in Quickbooks for PC but not in MAC' available: Yes (Solved).
Source: Intuit Community forum.

How do I record discounts from vendors gross as a part of cost of goods sold? I could do this in Quickbooks for PC but not in MAC: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

Support for Cost of Goods Sold
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Error Recovery for Cost of Goods Sold [Canada]
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