Hello there, @Ospreybob.
The way you obtain your Customer's Credit Card information is based on how you want to make your Customer feel comfortable and that it's secure. I recommend checking out what is qualified with PCI DSS (Payment Card Industry Data Security Standard) before making a final decision.
Here's a Community Article that provides more details about how you can save your Customer's Credit Card information in QuickBooks Online.
If you have additional questions or concerns, please don't hesitate and reach back out. Have a great rest of your week, Bob!
