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Apartment Mailboxes for Multifamily Buildings
Apartment mailboxes give every unit a locked compartment in one centralized location, which is what USPS expects at most new multifamily properties. This collection groups Salsbury Industries cluster box units, 4C horizontal mailboxes and outdoor parcel lockers for apartment complexes, condos and mixed-use buildings. Units marked USPS Access let the carrier open the whole unit with a postal lock while each resident uses a separate key.
- Cluster box units (CBUs): freestanding units with 4 to 16 tenant doors plus parcel lockers, in standard and Regency decorative styles
- 4C horizontal mailboxes: built to USPS Standard 4C, including free-standing models
- Outdoor parcel lockers: 2 or 4 extra package compartments
- Engraving and placards for unit numbers
Compare details in cluster box units and commercial mailboxes, or see 4C free-standing mailboxes.
How to choose apartment mailboxes
- Count units: plan one tenant door per apartment, then add room for growth.
- Plan for packages: each CBU type has a set number of parcel lockers; add outdoor parcel lockers if residents get many deliveries.
- Indoor or outdoor: CBUs stand outside on a concrete pad; 4C units usually go in a mailroom or lobby wall.
- USPS or private delivery: units marked USPS Access serve postal delivery; the free-standing 4C model listed here is Private Access, meant for in-house mail distribution.
- Look: Regency decorative CBUs and pedestal covers suit properties with design standards.
Salsbury CBU types at a glance
- Type I: 8 doors, 2 parcel lockers
- Type II: 12 doors, 1 parcel locker
- Type III: 16 doors, 2 parcel lockers
- Type IV: 13 doors, 1 parcel locker
- Type V: 4 doors, 2 parcel lockers
- Type VI: 8 doors, 4 parcel lockers
Before ordering, contact your local postmaster to confirm the delivery mode and location, and review our USPS regulations page for the 4C standard. Need help with sizing or a multi-unit order? Call +1 888 345 9545. Units ship from the manufacturer.
Frequently asked questions
What type of mailbox do apartment buildings need?
New apartment buildings usually need USPS approved centralized mailboxes: either 4C horizontal mailboxes, often installed indoors, or cluster box units (CBUs), which are freestanding and usually outdoors. Older buildings may have 4B vertical mailboxes. Your local postmaster decides which delivery type serves your building, so contact them before ordering.
What is the difference between a CBU and a 4C mailbox?
A cluster box unit (CBU) is a freestanding pedestal-mounted cabinet, typically installed outdoors on a concrete pad, with tenant doors and parcel lockers. A 4C horizontal mailbox is built to USPS Standard 4C and is usually recessed or surface mounted in a wall or set in a free-standing enclosure. Both are approved for multifamily delivery.
How many doors do I need for my apartment complex?
Plan one tenant door per unit, plus parcel lockers for packages. Salsbury CBUs range from 4 doors with 2 parcel lockers (Type V) to 16 doors with 2 parcel lockers (Type III). Larger complexes combine several CBUs, and adding outdoor parcel lockers gives more package space. Call us if you need help sizing.
Who is responsible for apartment mailbox maintenance?
In most cases the property owner or manager buys, installs and maintains apartment mailboxes, including replacing tenant locks and keys. USPS installs and controls the master or arrow lock it uses to open the unit. Check your postmaster's requirements and your local rules before you buy or replace a unit.
Can I engrave unit numbers on apartment mailbox doors?
Yes. We offer Salsbury custom door engraving and custom engraved self-adhesive placards for cluster box unit and outdoor parcel locker doors. Each door should show its unit number so the carrier can sort mail accurately. Order engraving with the mailbox unit so everything arrives ready to install.
