I have a client who needs to get paid as a one-off transaction by credit card. Is there any easy (cheap) way to do this within QBO platform?

Hey sallyway2013,

Thanks for turning to the QuickBooks Community for support. Being able to accept payments from clients is an important step in running your business. I can provide some information on payments.

QuickBooks Online is a great software to have. Not only does it make running your business easier, it also allows you to accept payments from your customers. There are two ways to take payments in QuickBooks. The first option would be the Payments feature, The fee for the Payments feature is, 2.9% plus 0.25$ per transaction, it processes within 24-48 hours. Follow these steps if you would like to set up Payments in QuickBooks Online. The second option would be bank payments. There are no fees for the bank payments option. However, you do need to have the Payments feature active. Don't worry, there is no charge for having the Payments feature active. Here is an article that will help you understand bank payments. 

If you have any other questions, feel free to reach out here.