Invoice to payout a loan contract

Hello,

I have a contract that is changing service providers and I have been asked to provide an invoice so it can be paid out by one provider and then it will show as 'paid' by the new provider and the new contract will begin, and thus our monthly installment payments.

This is essentially a liability (phone equipment loan) and I am unsure how to show the 'sale' and 'payment' when it is not actually a sale at all.  I understand the provider needs an invoice, but I would think this is a GJ entry on my end.

I hope this makes sense.  Can I provide the invoice, then credit it once paid and enter as a GJ in my system?

Regards

Natalie