Payment frequencies on both legs of an interest rate swap can it be customized to meet the specific needs of the counterparties. This flexibility also means that fixed and floating payments don't necessarily occur at the same intervals. For example, you might have fixed payments occurring annually while the floating rate is paid quarterly or semi-annually as shown here. In the past when IBOR based swaps were more common, the payment frequency on the floating leg was generally aligned with the tenor of the underlying reference rate. So if the reference rate was six month LIBOR, the floating legs interest rate would reset and be paid every six months. This alignment is still the standard for IBOR linked swaps today. Additionally, for these IBOR based swaps, the floating rate is often described as being set in advance and paid in arrears. What does this mean? Essentially, the relevant IBOR rate, also referred to as the IBOR fixing at the beginning of the interest period determines the interest rate applied to the floating leg. However, the payment based on that interest rate happens at the end of the period. For example, if today is the fixing date for a swap with semi-annual payments on the floating leg linked to six month EURIBOR, today's durable fixing will determine the cash payment made in six months time. So the rate is known at the beginning of the period set in advance, but it's paid at the end in arrears. But how do interest rate swaps work when one of the new risk-free rates or RFRs, is the reference rate. Remember, RFRs are overnight rates, meaning they only apply for a one day period. So do we still align the payment frequency with the underlying rates tenor? No. Since that would mean daily payments on the floating leg, which would be highly inefficient and costly. Instead, the standard approach is to reset the reference rate daily, but to make payments at much longer intervals, such as quarterly, semi-annually, or even annually. Since the payment amount is determined by all of the RFR fixings over the interest period, the payment amounts will only be known at the end of the period, and that's when it will be paid. So the rates and payments are both finely known and paid in arrears.