From AYSO Wiki
Deferred Income is money received for services which has not yet been earned. (Example: a new year registration is open, and one receives payment for the new year. We will record it as deferred income until the new year begins.)
On 6/30/xx of each year do a journal entry to record deferred income. And then do another journal entry on 7/1/xx of each year transferring the income from a liability to revenue recognition.
Link: QB Journal Entry Video