Can you add a transaction to a transaction if so how?

Hello Taylorstdriving.Thanks for contacting the Community! Do you mean to add a line to an existing invoice for example? Thanks

When I send a invoice and they pay it how do I link that to the bank transaction that shows up as income?

If you have the bank account connected and the amount is the same it should bring up a match in the banking section if you find it is not doing that you can click on the line of the transaction in banking and go to find a match and it should bring that invoice up and when you match it will close the invoice as paid and add the income.Any Q's just ask here