Once you have added an inventory item you can attach a pricing Co-efficient to the item.
Download the Inventory group, the list will contain inventory items that have a green background, this means that no pricing co-efficient has been added at this stage
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When adding (A operation column) pricing to new Inventory Items you need to enter a Date in to column E The date in the "Date From" column this is the date the price will be effective.
The PKID column should be blank or can show as multiple zeros.
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here will apply to any orders from the date. If you enter a date in the past any orders that contain this inventory item will have the new price added.
Leave the PKID column (A) as is.
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Note if the spreadsheet is not green and contains a unique number in the PkId Column a Price already exists, you can add a new one but you must ensure the date effective has been updated.
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Try to not back date pricing co-efficients as it may affect previous orders in that date range.