Yes, you can, @ajsplumbingtilin.

Before you can accept credit card payments in QuickBooks Online (QBO), you'll want to ensure you've signed up for QuickBooks Payments.

I'll show you how:

1. Log in to your QBO Simple Start version.
2. Go to the + New menu.
3. Select Invoice.
4. From the Payment options section, click Accept Card Payments link. 
5. Follow the on-screen instructions to finish the process and click Done.

You can also see this article for the complete details: How to accept credit card payments.

If you've already created your Payments account, I recommend contacting our merchant support team. One of our live agents can investigate your account and determine why your customers are unable to pay their invoices online. Simply log in to your Merchant account and reach out to them from there.

When you're finished, you might want to look into this resource to help you organize your transactions more efficiently: Categorise and match online bank transactions in QuickBooks Online.

I'm all ears if you have any other concerns about your invoice and payments. Simply leave the details in your reply and I'll take care of them for you. Keep safe and have a good one!

@ajsplumbingtilin 

If you run a service company in the UK, you can use a third party app to integrate with QBO and accept payments with Visa, MasterCard, American Express, Diners Club (International), Discover (Domestic) and Direct Debit (BACS).

https://get.practiceignition.com/quickbooks