why is a customer deposit a liability
10 days before we perform the service, we charge the $800 (+tax) final payment to the customer. This needs to be posted as a liability (unearned income/revenue), not as revenue/income, because we haven't performed the service yet. We would also like to send the customer an updated estimate showing the $1,000 (+tax) cost, minus the $200 (+tax) deposit, minus the $800 (+tax) final payment, equals $0 outstanding.