Punggol is young, so its pool of landlords is narrower than an older town's. Many HDB owners here are still inside their minimum occupation period (the years an owner must live in the flat before selling or renting it out whole) and live in the flat.
Even after that period, letting a whole flat needs HDB's approval, and the rules depend on the flat class.
That leaves condominium owners around the Waterway and Punggol Central, executive condominium owners whose period has ended, and owners of the first Punggol flats built around the two LRT loops.
Tenants come from the SIT campus and the Punggol Digital District, from families renting while their own BTO flat is built, and from staff at the retail centres. Day-to-day management needs no CEA licence, but arranging the tenancy is estate agency work and does.