Reviewing your sales data in QBO and assessing spending limits allows you to create a practical monthly revenue forecast, Denissa. If you're manually recording customer payments and expenses in QuickBooks Online, there's no limit on the amount you can enter per day or month.

However, if you're accepting payments or processing customer orders through a third-party payment or sales application, the amount limit will depend on the specific third-party service. I recommend reaching out to them to confirm their limits.

Check out this article for a reference:  Use reports to track cash flow in QuickBooks Online. It gives you a guide on how to view the status of sales transactions, open invoices, and paid invoices.

Additionally, you can also create budgets, which give you an overview to help compare your actual income.

I'm just a message away if you need help with customer payments or anything related to QuickBooks. I'm here to support your success. Take care!