Can a user make a refund for the sales of the service in the QuickBooks online?

I'm here to guide you on how a user can make refunds in QuickBooks Online, Khurram1010.

Primary and company admins get all access rights. Therefore they can process refund anytime for your sales transaction. The same with the standard user role. QuickBooks lets you choose the access rights for your user. You'll just have to make sure to give them at least limited rights so they can enter estimates, invoices, sales receipts, credit memos, and even refund. I've added a specific screenshot so you'll be easily guide: 

To give you a more complete description on the roles that count toward user limits, I've got this article for your guide: User Roles and Access Rights In QuickBooks Online. Once you're able to customize user roles, you can process refund in QuickBooks. Since this varies from different scenarios, go through this article for your reference: Record A Customer Refund In QuickBooks Online.

In addition, QuickBooks download the latest bank transactions and tries to look for a match to what you've already entered in QuickBooks. To know more on how this works, consider reading this article for more information: Categorize and Match Online Bank Transactions In QuickBooks Online.

Drop a comment below if you have any concerns about refunds. I'm always right here to assist your need.