A subtenant isn't a "less-than" tenant. Subtenants are simply tenants renting underneath the unit's original tenant, called the primary tenant. In contrast, primary tenants rent directly from a landlord or property owner.
1. Subtenants can coexist with primary tenants
You might assume that, if you rent your unit to a subtenant, you have to move out. However, there's no reason that subtenants and primary tenants can't coexist. In fact, oftentimes, subtenants rent a single room or guest suite while the primary tenant continues to live in the rest of the apartment. Subtenants can be the lone occupant of a unit, however. It's all up to the primary tenant, or subletter.
2. You need to consider the legality of subtenants
Most of the time, it's legal to rent to a subtenant. However, some leases will have provisions that prohibit the act of subleasing. If your lease doesn't have a specific clause relating to subtenants, but you still feel uneasy, you can simply contact the property owner and ask.
3. There are several reasons for leasing to a subtenant
Some people will obviously prefer to live alone. But, for the rest, bringing in a subtenant can have a number of benefits. For starters, it decreases the rent cost or relegates it to someone else wholly. It also helps keep the unit safer as it may be occupied while you yourself are away. Lastly, subtenants help you build a strong rental reference history, even if you don't actually live in the unit.
A subtenant can be nice, but be careful
Subtenants can be extremely helpful and fulfilling. However, if you're considering renting to a subtenant, you should be careful. Even if you think you know someone, keep in mind that they're ultimately going to be living in a space that's rented under your name. A roommate agreement or contract is never a bad idea in this case.