Some of my customers want the ability to track which of their clients an invoice and payment is in reference to. For invoices I have a custom field I use to fill in their clients name so that is shows on the invoice and when they pay via paypal I record the client name in the reference field so that is shows up in the transaction history.

Is their a way to send more invoice details to paypal to be recorded in the transaction history, specifically what shows up in the subject field of a paypal payment. I would like to be able to send the information placed in one of my custom fields (which I use to record a project name) and have that show up in the subject line of the paypal payment.

Similarly I would like to be able to add that information to the invoice email template. Is their an option for adding the custom field text as a placeholder in the template.