How can I enter bills from lat year ? I tried to do it but it tells me that I cannot enter with a date before the inventory

I want to fix the quantity as-of date error right away, @gabi-latintechll.

Don't worry, I have a way to eliminate the as-of-date prompts to ensure you can enter your last month's bill in QuickBooks Online successfully.  

With this, I'd recommend modifying your inventory as of a date in the system. Let me show you how: 

1. Go to the Reports menu on the left side. 
2. Type Inventory Valuation Detail in the search box, and press Enter your keyboard. 
3. Click the Customize button. 
4. Pick the appropriate Report period in the drop-down. 
5. In the Rows/Columns, select Date, Transaction Type, Num, and other details. 
6. Hit Run report. 
7. Locate the item and click the START or Inventory Starting Value hyperlink. 
8. Modify the As of date, then click Save and close. 

For more information about customizing, see this link: Run and customize reports in QuickBooks Online.

Then re-enter the bill. The message should not come up. For more details, see this link: Enter bills and record bill payments in QuickBooks Online.

You can also bookmark these articles below to know the different inventory reports and how to modify quantity: 

• Use reports to see your sales and inventory status
• Adjust inventory quantity on hand in QuickBooks Online

Leave a message below if you need additional details or explanations about managing inventory items. I'm always available to assist you. I wish you and your organization continued success, gabi-latintechll.