I have created sales invoice. Before I have received some payments from customer in advance which I want to show matched against my sales invoice.
Is there any way I can add money received to the invoice without adding bank account?
How has the customer paid you then?! Cash? Create a cash account…
Also, you said customer has previously paid you money in advance, how did you record this transaction?
See some guides:
How do I record customer prepayment?
http://www.manager.io/documentation/customer-prepayment
How do I match customer advance payment with sales invoice?
http://www.manager.io/documentation/customer-advance-payment-accounts-receivable