Hello MV12,
Thank you for your post. I want to greet you with a warm welcome to the MYOB Community Forum.
When a customer has paid, it will be recorded as "CR:", and you can also see this under the Activity History of the invoice. The CN is the Contract Reference number which is an additional reference number for e-invoicing.

If you need further information about invoices, here's a helpful article on Creating invoices.
Please feel free to post again. I'm happy to assist further.
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