whenever I create a sales invoice, the (COGS) is not recorded, and the item quantity is not deducted from inventory. These two fields always show 0

I understand how frustrating it is to have your workflow interrupted by these recurring situations.  To resolve this, please ensure the item's type is set to track inventory, or make it Inactive and create a New Inventory item to restore correct calculations.
 

Here’s how:
 

Step 1: Check the Item type
 

1. Navigate to the Gear icon > Products and Services.
2. Find the item used on the invoice and click Edit.
3. Make sure the item type is set to Inventory (not Service or Non-inventory)
4. Confirm the following fields are filled in:
   • Initial quantity on hand
   • As of date
   • Inventory asset account
   • Cost of Goods Sold (COGS) account
5. Click Save and close.

Step 2: Inactivate and Recreate the Item
 

1. In your Products and Services list, locate the item.
2. Click the dropdown arrow next to Edit and select Make inactive.
3. Click the New product/service button at the top right of the screen.
4. Select Inventory as your item type.
5. Fill in the item details, ensuring you link the correct Asset, Income, and Expense/COGS accounts.
6. Save your new item.

If you check the original item and see it is already set as an Inventory type and the issue still persists, I recommend contacting our Live Support team so they can look closely at your account and ensure that the account mapping is syncing correctly.

Don’t hesitate to reply below if you have more questions about QuickBooks. We’re here to assist you.