You can choose to overwrite all values for each product or service with the same name when importing items in QuickBooks Online (QBO). I'll show you how.
From the Gear icon, chose Import Data under Tools.
Select Product and Services.
Click on Browse, locate your excel file, and select Open.
Choose Next and map your item fields to QuickBooks fields.
Click on Next and mark to select the Overwrite all values for each product or service that you import with the identical name. (This can’t be undone.) box.