I think we are talking more in a financial/P&L sense here. Our banking systems accrue interest & fees for e.g. loans and deposits and post to the relevant internal accounts so that the P&L is always up to date. This is probably for the accounting system of a company, but I'd still stick with accrual, because a deferral of interest would mean that it is paid at a later point while accrual means that the interest is calculated so that one knows what is due to be paid or received and allows for these amounts in projections, forecasts, etc.