Welcome to the Community, Sarah. I'll share some steps on how to Opt out of a pension scheme in QuickBooks Online Core Payroll.
The Pensions Regulator states that when an employee chooses to opt out of an auto-enrolment pension, they are entitled to receive a full refund of any contributions they have made into the pension scheme within a month of receiving a valid notice.
To opt an employee out of a pension scheme, here's how:
Sign in to your QuickBooks Online Payroll account.
Go to Payroll, and then click on Employees.
Choose the specific employee.
Select Workplace pension, loan & other deductions.
Click on the Pencil icon.
Turn off Enrolled in pension. If no refund is due, hit on Cease membership.