How to Open an Old Safe You Inherited or Found

Short answer: How to open an old safe starts with paperwork, not the dial. First make sure it's yours to open — inherited through an estate, or included with a house you bought. Then search for the combination in estate papers, old manuals and safe deposit boxes. Identify who made the safe and its lock, and contact them if they're still in business. If none of that works, hire a qualified safe technician, such as a SAVTA member, who will want to see proof that the safe is yours. There's no factory code or trick that legitimately opens someone's old safe.

This page is for safes that came to you without instructions. If you bought the safe yourself and lost the combination, the locked out of a safe guide is closer. If you're thinking of replacing it, our home safe guide covers what modern ratings mean.

Step one: make sure it's yours to open

This is the part people skip, and it's the part a good technician will ask about first.

• Inherited safe. If an estate is still being settled, open it with the executor's agreement, and keep a record of what's inside.
• Safe that came with a house. Check whether your purchase contract included it. If you're unsure, ask your real estate agent or attorney before you open it. We don't give legal advice; they do.
• Safe in a rental. It belongs to the landlord, or to a tenant who left it. Not you.

Keep the documents that show your connection to the safe: the will or estate papers, the closing documents, the deed. You'll need them for any manufacturer and any reputable technician.

Look for the combination where people actually kept it

Old safes were set by someone, and that someone often wrote it down. Look before you pay anyone.

• The manual or original paperwork. Modern makers put it there: SentrySafe prints the combination on the back of the owner's manual, and Honeywell attaches a combination sticker to the manual's first or last page. Older owners kept papers too.
• Estate papers and files. Wills, letters of instruction, address books, filing cabinets.
• A safe deposit box. A retailer's lockout guide recommends keeping a backup combination in a safe deposit box or with important documents. Some people did.
• The previous owner, or their family. If the safe came with a house, the seller may simply know.

A combination is three or four numbers on a scrap of paper. It can hide anywhere. It usually hides in the desk.

Identify who made the safe, and who made the lock

Look for a maker's name on the door, a serial plate, or labels inside paperwork. The lock may come from a different company than the safe; Sargent & Greenleaf, for example, makes mechanical locks used on many safes.

If the maker is still in business, contact them with the model, serial number and your proof of ownership. Today's makers keep records for registered safes — Liberty, for instance, says registration creates a record of ownership it can refer to if you lose your combination. Whether a company still holds records for a decades-old safe is a question only that company can answer. Ask.

If the maker is long gone, skip to the technician. There's no customer service line for a company that closed before you were born.

Mosler safe default combination and other shortcuts

Searches for a "default combination" come up constantly with old safes, often naming a specific brand. This page doesn't list factory combinations, and here's why they're the wrong thing to hunt for.

Factory combinations are meant to be temporary. Sargent & Greenleaf's instructions say a lock may arrive set to a factory shipping combination, and give owners the procedure to set their own. A safe that guarded someone's papers for decades should not still be on its shipping numbers. And if it were, the safe still isn't yours by virtue of guessing.

The same goes for "antique safe cracking." What a qualified technician does with an old safe is skilled work, done for owners who can show the safe is theirs. It isn't a hobby project, and this site doesn't describe how it's done.

If you have a combination: dial it the right way

Found a combination? Dial it slowly and carefully. Old locks aren't all dialed the same way, so the steps matter.

• Three numbers. Sargent & Greenleaf's three-wheel procedure: left to the first number the fourth time, right to the second number the third time, left to the third number the second time, then right until the dial stops.
• Four numbers. S&G's four-wheel procedure starts to the right, stopping the fifth time on the first number, and alternates from there.

Other makers differ; SentrySafe's fire safe dial, for example, starts to the right with three passes of zero. Our guide to opening a combination safe has full steps and S&G's dialing rules: view the dial straight on, and never back up past a number.

If the dial turns roughly or not at all, stop. S&G says never force the dial — a dial that won't turn under light-to-moderate pressure needs a qualified safe technician. That's especially likely on an old lock nobody has serviced. S&G recommends annual servicing for every combination safe lock. Forty years is a long gap.

Old safe, no key: the same route

Some old safes use a key lock, alone or alongside a dial. If the maker still exists, ask about a replacement key. First Alert's guide, for example, says the key number engraved on the keys is required for a replacement, along with the model and serial. For an old safe with no maker and no key number, a licensed locksmith or safe technician is the answer. See how to open a safe without a key for more.

Hiring a safe technician for an old safe

ALOA's consumer page says SAVTA members can repair and maintain safes and can open a safe if you're locked out. SAVTA's site has a search for a qualified technician.

Before anyone starts:

• Check the license where your state requires one. California's tips say locksmiths there must be licensed and carry a pocket copy of the license.
• Get an estimate when you call, and an itemized receipt afterward.
• Confirm the company that arrives is the one you called, per ALOA.
• Be wary of instant drilling. ALOA says a locksmith who goes straight to drilling is often a sign of a scammer. S&G's guide says 80 to 90 percent of safe lockouts can be overcome without penetrating the safe.
• Ask for servicing once it's open. ALOA says not to lubricate a safe lock yourself, because it needs specific lubricant and application.

Bring your proof of ownership to the appointment. The technician will want it. If they don't ask, ask yourself why not.

Here's the catch: opening it may cost more than the safe is worth

An old safe is heavy, and heavy isn't the same as valuable. A retailer's lockout guide suggests weighing the locksmith's estimate against the value of the safe and its contents. That comparison is worth doing before you book anyone.

And if it opens empty — which happens — decide whether to keep it. An old safe's fire protection is an unknown. UL's current fire standard for record protection, UL 72, is in its 17th edition, published January 2026. A safe from decades back was built, and rated if it was rated at all, against earlier rules. If you plan to store documents in it, a newer safe with a stated rating may serve you better.

Skip it if: when you don't need this guide

• You bought the safe new and lost the combination. See locked out of a safe.
• You know the combination and it's a modern safe. See how to open a combination safe.
• It isn't yours. Find the owner, the executor or the landlord first.
• You want to change the combination once it's open. See how to change a safe combination.

That's the old case, closed properly. Get the paperwork in order, search the desk, find the maker's name, and call a qualified technician who asks to see proof. Once it's open, have the lock serviced, set a new combination, and write it down somewhere better than the back of an envelope.