Occupancy caps
HDB caps the number of unrelated tenants per flat (and per bedroom) to manage overcrowding — the exact cap depends on flat type. Always check current limits before advertising rooms, as exceeding them risks enforcement action.
Registration is mandatory
All tenants, whether renting a room or the whole flat, must be registered with HDB. This isn't optional paperwork — unregistered subletting is an offence and can affect your future eligibility for HDB schemes.
Ethnic Integration Policy applies to tenants too
Subletting is also subject to EIP quotas by ethnic group and nationality at the block/neighbourhood level, similar to resale purchases — check availability before committing to a specific tenant if quotas are tight in your block.
Keep your subletting registration current and renew on time — lapsed registrations are a common, easily avoidable compliance issue.