How do I add default payment detailst to an invoice please?
Not sure what you mean by 'default payments' but you can either add an payment to an invoice directly by clicking the Payments button on the invoice page or enter a Deposit/Retainer (on the Project Details page) and then apply that deposit/retainer to multiple invoices over time.
Here's a video about the retainers: http://cloudsupport.designerlogic.com/support/solutions/articles/5000699600-project-retainers-and-deposits
If you're looking for something else let me know and I'll see what we can do-
Thanks - I mean - add default payment information ie bank account details to an invoice so that they appear on the invoice.
If you mean you want each invoice to have your bank account info for payments then you'll want to put them in the Invoice's Terms and Conditions (shows up at the end of each invoice). You can set the default in Account/Settings (top right menu) Terms and Conditions. Just edit the one for Invoice to include your bank account info. Then each NEW invoice will have this info on it.
Keep in mind you can always change the Terms for an individual invoice in the Edit part of the invoice, if desired.