Multi-Family Mailboxes: Double, Triple & Quad (USPS-Approved)

Learn More About Multi-Family Mailboxes

What Are Multi-Family Mailboxes?

Multi-family mailboxes are shared mailbox systems designed to serve two to four residences from a single installation.

Our multi-family mailbox systems combine performance with curb appeal, featuring USPS-approved units from trusted brands like Salsbury, Mail Boss, and Whitehall.

Available configurations include:

• Double, triple, and quad mailbox sets

• Select options for five or more mailboxes, depending on model

• Wall-mount or curbside post installation

• High-security locking options with parcel compartments

All units are fully customizable with finishes, address plaques, and newspaper holders. Fast shipping and compliance with national delivery standards are included.

Pick Your Perfect Mailbox Configuration: Double, Triple, Quad, and Up to 6 Units

The right mailbox configuration depends on how many residences you are serving and how the mailboxes will be accessed. Before choosing a unit, it helps to consider spacing, layout, and daily use.

Multi-family mailbox systems are commonly installed in a few standard layouts, including side-by-side, back-to-back, or multi-arm post configurations, depending on the post system and available space.

Here are a few factors to think through:

• Number of residences sharing the mailbox

• Available space along the curb, sidewalk, or wall

• Side-by-side, back-to-back, or multi-arm post layout preferences

• Clearance for doors, lids, and mail carrier access

• Placement near driveways, walkways, or entrances

Double Mailbox Unit (2 Mailboxes): Best for Duplexes and Shared Driveways

If you’ve got a duplex or two homes next door to each other, a double mailbox just makes life easier. It keeps the front view tidy and installs without much fuss.

These setups often include:

• A spreader bar or dual-arm post

• Space for two individual mailboxes

• A clean, symmetrical curbside look

In many cases, the mailboxes themselves are sold separately, allowing you to choose matching styles or finishes that suit the property.

Triple Mailbox Unit (3 Mailboxes): Small Multi-Family and Corner-Lot Flexibility

Triple mailbox units work well for small multi-family properties or locations where three residences share a single delivery point.

When selecting a triple unit, it is important to account for:

• Arm length and spacing requirements

• Door and flag clearance to prevent interference

• Placement that allows easy access for residents and mail carriers

Triple mailbox setups work well on corner lots or anywhere you need a little more freedom in where the boxes sit.

Quadruple Mailbox Unit (4 Mailboxes): Fourplexes and High-Use Delivery Points

Quad mailbox units are designed to serve four residences and handle higher daily mail volume. Because of the added weight, stability is especially important.

These units are often chosen for:

• Fourplex properties

• Shared delivery points with frequent use

• Clear address labeling for multiple households

Durable materials and secure mounting help ensure long-term performance.

Mounting and Installation for Multi-Unit Mailboxes

Mount it properly so it’s easy to reach, stays steady for the long haul, and your mail gets delivered without hassle. Before you buy, measure the spot you’re working with and think about how you’ll use the mailbox day to day.

Keep these considerations in mind:

• Measure wall width or post placement area

• Allow clearance for doors or lids to open fully

• Account for height and depth near entryways or overhangs

• Match the installation type to walk-up or porch delivery

In-Ground Mount Posts

In-ground posts are a popular choice for curbside installations. They are set directly into concrete, providing strong, long-lasting support.

These posts are commonly used when:

• A permanent installation is preferred

• The mailbox is placed along the curb

• Extra stability is needed for multi-unit systems

Surface Mount Posts

Surface mount posts attach to existing concrete pads or paved surfaces. They are often used where digging is not practical.

Surface mount posts are a good option when:

• Installing on sidewalks or slabs

• Ground excavation is restricted

• Flexibility in placement is needed

Mailbox Spreader Bars and Adapter Plates for Double Mailbox Installs

Spreader bars and adapter plates connect two mailboxes to a single post. The right choice depends on your space and whether you are using an existing post.

Use a spreader bar if you:

• Have an existing post and want side-by-side mailboxes

• Prefer a balanced, symmetrical layout

Use a dual-arm post if you:

• Are installing a new mailbox system

• Need a more integrated and stable setup

Compatibility basics to check:

• Post size

• Mounting bracket alignment

Confirming compatibility ahead of time helps ensure a secure installation.

Weatherproof Materials and Finishes for Long-Term Use

Multi-family mailboxes are exposed to weather year-round, so choosing durable materials and finishes helps protect both the mailbox and its appearance over time. Climate, sun exposure, and surrounding design elements all play a role in selecting the right option.

Color and Finish Options: Black, Bronze, White, Sandstone

Mailbox finishes aren’t just about looks, they can help with durability, too. The best pick usually comes down to how much sun hits your mailbox, the style of your home, and what’s nearby (like railings or porch lights).

Black

• A classic, versatile finish used across many property types

• Holds up well in high-sun areas and tends to show less dirt

• Pairs easily with black railings, fences, and exterior hardware

Bronze

• Warm, decorative appearance with a more traditional feel

• Works well with bronze or oil-rubbed fixtures and metal accents

• Often chosen for properties where curb appeal and detailing matter

White

• Clean, high-contrast look that stands out against darker exteriors

• Common in residential communities with lighter color palettes

• Best suited for areas where regular cleaning helps maintain brightness

Green

• Subtle, traditional finish often used in residential neighborhoods

   

• Blends naturally with landscaping and outdoor surroundings

   

• A popular choice for properties seeking a classic curbside appearance

Custom address numbers or lettering are available as optional add-ons for many mailbox styles, helping keep multi-unit setups clearly labeled and easy to identify.

Security and Access: Locking Double Mailbox Units and Safer Mail Retrieval

Security needs vary by location, but the right access style helps reduce mail theft and maintain easy daily use.

Standard access

• Quick mail retrieval

• Limited protection in shared or high-traffic areas

Locking access

• Added security for shared delivery points

• May include reinforced doors or anti-pry features, by model

Security checklist

• Lock type

• Door construction

• Mounting stability

• Visibility

Choosing the right setup helps balance security and convenience.

Multi-Family Mailbox Units vs Cluster Mailboxes: Which Do You Need?

Multi-family mailbox units are made for small shared setups; usually for two to four homes. You’ll typically see them installed at the curb or near a building entrance.

Cluster mailbox systems are used for larger apartment buildings and often include centralized access and parcel lockers. If your property serves only a few units, a multi-family mailbox is usually the simpler and more appropriate option.

Capacity Planning: How to Choose the Correct Multi-Family Mailbox Size

Mailbox capacity should match both daily mail volume and available space. Planning ahead helps avoid overcrowding and access issues.

Key factors to review include:

• Letter and small parcel volume

• Door size and interior depth

• Clearance for opening doors or lids

• Setback from driveways and walkways