July 03, 2019 16:54 Updated Follow There are several things that factor into the final cost of extra service. We suggest you read Buying Extra Service Credit if you are a member of PERF or TRF. For other funds, . Related articles I was a substitute teacher. How can I add this service to my account? Do you accept credit cards? If I become disabled during my employment, am I protected from termination? What if I don't know my user ID and passcode to log on to my PERF or TRF account? What happens if the date my pension is normally deposited is on the weekend or a holiday?