Can I remove multiple old customers?

Hello there, @KarenFritzFryer. I'd be happy to share with you the steps on how you can batch remove multiple old customers in QuickBooks Online (QBO).

In QBO, you can remove a customer from the list by making them inactive. Please note that when you make a customer inactive, it will also remove its sub-customers (if it is a parent customer). Also, the transactions linked with them will stay in your company data reports. To remove multiple customers at once, you can follow these steps:

1. Sign in to your QBO account and go to the Sales menu.
2. Next, select Customers.
3. Check the box beside each old customer you have to remove.
4. Once done, select the Batch actions dropdown.
5. Then, choose Make inactive and click Yes. 

To learn more details about managing your customers, please visit this article: Add and manage customers in QuickBooks Online.

Getting a list of your customers’ outstanding balances will help you determine how much still due and how long they’re past due are. You just simply need to run the accounts receivable ageing report to have this data. 

If you need additional assistance in removing customers at once in QBO, feel free to post a reply below. I'd be happy to help you further. Have a good one.