We've received in advance money to create a software.That take about a year to create.My question is how do we record the invoice, money received and release part of the money on monthly basis in SAGE 50 ?
I think you will want to recognise the income when it is earned so you could debit bank and credit deferred income (as a liability in the balance sheet). You could certainly release on a monthly basis by debiting deferred income and crediting sales. It may be that you have a balance remaining at the year end and so you will not get taxed on it until it is recognised as income.