Purchase of ERP software

Hi, Appreciate if someone could help me on this.

Lets say a client has ordered a specialized software costing $1,500. As of the year end, software has not been delivered yet and client has made an advance payment of $1,000.

The only entry made in regard of this transaction is recording of advance payment.

My question is whether we need to accrue the remaining amount of $500 in the books at the year end?. 

Thank you.