An invoice I have created for a client is deducting money, so giving a lesser amount owed?

Good day, acebuildersservi.

 Allow me to provide additional information about showing a credit to an invoice in QuickBooks Online (QBO). 

QuickBooks has a function that applies available credits to open invoices. Thus, causing the invoice to be paid automatically.

Here's how we can turn this function off:

1. Click the Gear icon.
2. Under Your Company section, select Account and Settings.
3. Select the Advanced menu.
4. Under Automation, turn off the Automatically apply credits feature.
5. Click Save then turns it on again.
6. Hit Save.

You can use this article on how to apply for a credit and delayed credit: Enter and apply a credit memo or delayed credit.

Also, you may use this link to remove a credit from an invoice or bill: Remove or unapply a credit from an invoice or bill.

I've added this article in case you want to learn how to customize invoices in QBO: Customize your invoices, estimates, and sales receipts in QuickBooks Online.

Keep me updated on how it goes. I'll be around to help if there's anything else you need with applying  credits. Wishing you well.