Dear Fiend, hello and welcome..
If you have invoiced him in December, then it would be sales of 2012. The amount would show as receivables as current assets in balance sheet ending 2012
I hope this helps...Rate this answer POSITIVELY IF you are done with this and if this helps and satisfies you as this is the only way we get compensated for assisting you. You may use "CONTINUE CONVERSATION" to revert with additional queries if you have or if I have missed out on any aspect of your question.