Did you know that you can add a link to your invoices that your clients can select to pay you online? You need to have online payments enabled in your QuickBooks Online account and you should contact QuickBooks Online support for assistance with this.
On your invoice imports into QuickBooks Online using Transaction Pro Importer if you want this link to be enabled on the invoice either provide the letter Y in your import file or as a default value mapped to the QuickBooks field, AllowIPNPayments.
There are two current methods that you can allow users to pay online either via Credit Card or via Online ACH Payment. Provide the letter Y if you wish for the particular payment method to be available to customers or to turn the option off provide the letter N. The two fields in the mapping are listed below.