Deferred Revenue in ERPnext

Hi. I have problem with recognizing deferred revenue in ERPNext. Based on IFRS, revenue can only be recognized after completing works or % of work progress is completed. However, we might billed our fee in advance or late to bill our fee. So we need to recognized deferred revenue whether it is Unbilled Revenue (an asset account for the case that we already fulfill our service, but not yet bill the fee) or Unearned Revenue (a liability account for the case that we billed our fee before we complete service or before we start to work on the project. As we have many clients and project, we will need to keep track the balance of Deferred Revenue by client. How do we do it in ERPNext?