Replacement
DIY or Professional Install? Choosing How to Replace Your Mail Slot
Most replacement mail slots, including the Brass-Seal Forged Brass Mail Slot System, are designed to fit an existing opening rather than require a new one. That single fact is why many homeowners install one themselves without hiring anyone, and why it's still reasonable to hire a professional if you'd rather not.
What the Job Actually Involves
Replacing a mail slot is generally a straightforward hardware replacement rather than a door modification project. In most cases, the existing hardware is removed, the replacement is positioned using the supplied template, pilot holes are drilled if needed, and the new hardware is fastened into place. Because the existing opening is reused, there's no cutting, no framework, and no structural change to the door itself for a standard replacement.
For a typical replacement, a standard drill and screwdriver are generally the only tools required. A precision drill template is included with every Brass-Seal system, allowing you to see exactly how the hardware will mount before drilling.
When DIY Makes Sense
Angi's guidance on comparable small hardware jobs, like deadbolt installation, frames DIY as reasonable for basic replacements on a standard door, and that framing applies just as well here.1 DIY tends to make sense when:
- You're comfortable using a drill and following a template.
- Your measured opening matches a standard Letter or Magazine size. See the sizing guide to check.
- Your door is a standard exterior door, not a reinforced security door.
When to Consider a Professional
The same Angi guidance flags smart or high-security hardware, new installations rather than replacements, and specialty doors as better suited to a professional.1 Applied to a mail slot, that translates to a few specific situations:
- Your measured opening doesn't match either standard size. The sizing guide recommends contacting BOTA directly in that case, but a pro can also assess options on site.
- Your door is under historic preservation review. See the historic door compatibility guide for what that can involve.
- You're not confident about alignment or drilling into your specific door material.
A locksmith or handyman familiar with door hardware can typically install a replacement mail slot in a single visit. See the cost guide for what comparable small hardware jobs typically cost.
Frequently Asked Questions
Do I need to cut a new hole in my door?
No, for a standard replacement. Most replacement mail slots, including the Brass-Seal, are sized to fit an existing opening.
What tools do I need?
A standard drill and screwdriver. A precision drill template is included with every Brass-Seal system to mark placement before drilling.
How long does installation take?
A single unit installation is generally a short, one-person job once the template is in place. A Paired System, with hardware on both sides of the door, takes longer than a single unit but is still a same-visit job for most installers.
Sources
- Angi. "How Much Does It Cost to Install a Deadbolt? [2026 Data]." angi.com/articles/how-much-does-it-cost-install-deadbolt-locks.htm