Why is account receivable amounts assigned to the COS account?

Hello there, Kim-28.

I'm here to share details about your invoices.

We'll have to track the cost of sales of all your inventory items. When you create a sales transactions, the cost of products you sell will be recorded to the expense account you selected. 

You can verify it by checking the set up of your products. You can follow these steps:

1. Go to Sales and select Products and Services.
2. Find the item/product and click Edit.
3. You'll see the COS under the Expense account.

I've also added this link to learn more about inventory products in QuickBooks Online.

Please let me know if you need anything else. Stay safe and healthy!