How many customers can the app take and how can I delete a customer?

Welcome to the Community, lilnaco2000-gmai.

There's no actual limit with regards to how many customers you can add in QuickBooks Online (QBO) for both app and web version. On the other hand, we'll need to delete the customer by accessing QBO in the web. To remove a customer, you can make them inactive. This hides them from lists and menus and even if a customer is inactive, all transactions associated with them stay on reports. Here's how:

1. Go to the Sales menu.
2. Select the Customers tab.
3. Choose the customer's name to open their profile.
4. Tap Edit.
5. Press Make inactive and Yes to confirm.

If you see transactions for an inactive customer, it will say "Name (deleted)." To learn more about this one, see the Add and manage customers in QuickBooks Online article. Feel free to visit our Manage Customers and income page for more insights about managing your sales transactions and company income.

I'd like to know how you get on after trying the steps, as I want to ensure this is resolved for you. Just reply to this post and I'll get back to you. Have a great day ahead.