Where invoicing is generated from a Service Contract or a Request Contract, the final invoice does not have a reference to the original contract, which is a common requirement to display on the invoice document.

Currently, any invoices generated from the request contract create firstly an invoice preview, then a customer order and lastly the invoice. 

These are the references available:

1. On the Invoice Preview, the Work Task / WO number is available, but not the Request Contract
2. On the Customer Order, the reference is the Invoice Preview Number
3. On the Customer Order invoice, the reference is the Customer Order number

Ideally, there should be additional references available at all levels to the Request number and the Request Contract number, as well as Standard Command buttons to allow users to navigate to the source contract/Request / Work Task.