How can i adjust credit note against invoice? I am unable to adjust credit note.

Hello, shivani-jha-patl. I'm here to help you adjust a credit note in QuickBooks Online.

QuickBooks Online offers automation features, such as automatically applying payments to an invoice.

If this feature is turned on and your customer has an available credit, this will automatically link to your open invoice and the option to adjust the credit is unavailable.

To turn off this feature, here's how:

1. Click the Gear icon at the upper right corner and choose Account and Settings.
   
2. Go to the Advanced tab in the left panel.
3. Select Automation and remove the check-mark for Automatically apply credits.
4. Tap Save.
5. Hit Done.
   

After that, let's unlink the payment. See the steps below to complete the process.

1. Locate and open the invoice.
2. Click the 1 payment at the upper right corner and select the linked transaction.
   
3. Click More, and select Delete.
   

Once done, you can adjust the credit note when receiving the invoice payment. Here's an article with detailed steps in receiving the payment: Record invoice payments in QuickBooks Online.

I'll be around if there's anything else I can help you with. Don't hesitate to drop a reply below. Have a good.