Most people buying a safe focus on size and price, and skip the two numbers that actually matter: the fire rating and the cash rating. Get those wrong and you've bought a heavy box that looks secure but won't protect what's inside from a house fire or a determined burglar. Check both ratings before you check the price tag, and plan where it's going to be bolted before it arrives.
What does fire rating actually mean?
A fire rating tells you how long the inside of the safe stays below a safe temperature for whatever you're storing, during a standard test fire. Paper documents char above roughly 175°C (350°F). Most home document safes are rated for 30 minutes or 60 minutes at that standard. If you're storing anything on a USB drive, hard drive, or photo negatives, you need a media-rated safe, because electronics fail at a much lower temperature than paper does, often around 52°C (125°F).
Look for a rating from a recognised test body, such as UL (Underwriters Laboratories) in North America. A sticker that just says "fireproof" with no test standard behind it is a marketing claim, not a fact. A genuinely tested 30-minute UL rated safe typically costs more than an untested box the same size, and it's worth the difference if a house fire is the thing you're actually worried about.
- Paper documents. Look for a 30-minute or 60-minute fire rating tested to a recognised standard.
- USB drives, hard drives, backup media. Look for a media or "data" rated safe, these hold a much lower internal temperature.
- Jewellery and cash. Fire rating matters less here, cash rating and build quality matter more.
What is a cash rating and why does it matter more than fire rating for valuables?
Cash rating is an insurance industry figure. It tells you the maximum value of cash the safe is rated to hold under a standard home or business insurance policy, assuming the safe is installed correctly. It's based on the safe's construction, lock type, and resistance to attack tools, not how it looks. A typical domestic safe might carry a £2,000 to £6,000 cash rating (jewellery is usually insured at roughly 5 to 10 times the cash figure, but check your policy wording).
This is the number your insurer actually cares about if you ever need to claim after a break-in. If you keep more cash, jewellery, or watches in the house than the safe's cash rating covers, your claim can be reduced or refused, even if the safe itself did its job and wasn't opened. Before you buy, add up roughly what you'd store and buy a safe rated above that, not just below it.
If you're already upgrading the front door lock as part of a wider security tidy-up, it's worth reading our guide to deadbolt grades explained, since insurers often look at both the door hardware and the safe when assessing a claim.
How big a safe do you actually need?
Buy bigger than you think. People consistently underestimate how much goes into a safe once they start using it properly: passports, a spare phone, a backup drive, jewellery, important documents, maybe a handgun or two if you're licensed. A small desktop safe fills up fast and then things get left out of it, which defeats the point.
As a rough guide, a single filing cabinet drawer's worth of documents plus some jewellery and cash needs at least 25 to 40 litres of internal space. Anything smaller is really just a lockbox for a passport and a few papers.
Where should a safe actually be bolted?
A safe that isn't bolted down isn't a safe, it's a heavy box a burglar can carry out the door in under a minute. Floor and wall fixing points come standard on almost every quality safe, and skipping this step is the single most common mistake people make.
- Concrete floor, ground level. The strongest option in most houses. Expansion bolts into concrete are very hard to pull free without noisy, time-consuming work.
- Timber floor, upper level. Workable, but you need to bolt through the subfloor into a joist, not just into chipboard, or the fixing pulls straight out under force.
- Internal masonry wall. Good for wall safes, but check the wall is solid brick or block, not a stud partition with plasterboard over it.
- Avoid bedrooms and obvious spots. A safe under a bed or in a bedroom wardrobe is the first place a burglar checks. A utility room, garage, or an unexpected cupboard buys you time and surprise.
Bolting is also the step with the most risk of doing real damage if it's rushed. Drilling into a concrete floor without checking for underfloor heating pipes or cables, or drilling into a wall without checking for electrics, can cause an expensive repair on top of the cost of the safe. If you're not confident with a hammer drill and a stud and pipe detector, this is a job worth paying someone to do properly once.
Electronic lock or key lock, and does it matter?
Both are fine when they're good quality. A mechanical key lock has nothing to run flat and nothing to reset, but you need to keep the key somewhere safe and separate from the safe itself. An electronic keypad is faster day to day and lets you change the code any time, but check the battery compartment is accessible from outside the door, so a flat battery doesn't lock you out of your own safe.
If your existing safe's lock has started sticking, feeling loose, or taking several attempts to open, that's usually a lock problem, not a sign the whole safe needs replacing. It's worth getting it looked at before it fails completely with something valuable locked inside.
If you're not sure what size or rating fits what you actually need to store, or you want the safe bolted down properly without drilling into a pipe or a cable, that's a straightforward call out rather than a DIY afternoon. Have the make and model (or photos if you already own one) ready, along with a rough idea of what you'll be storing, and get in touch to arrange a visit. You can see more about how we work on our about page.
Frequently asked questions
Do I need a fireproof safe or a burglary safe?
Most home safes are built mainly for one purpose or the other, so decide what you're more worried about first. If it's house fires and you're storing paper documents or passports, prioritise the fire rating. If it's theft of cash, jewellery, or watches, prioritise the cash rating and build quality instead.
Can any safe just sit on the floor without being bolted?
Technically yes, but an unbolted safe under about 150kg can usually be carried out by two people in a few minutes. Insurers often specify bolting as a condition of the cash rating applying, so an unbolted safe may not be covered for its full rated amount.
How much does a decent home safe typically cost?
A small, basic fire-rated document safe typically runs $150 to $350. A properly cash-rated safe with a good lock and fire protection for documents and valuables typically runs $500 to $1,500, depending on size and rating, and that's before installation.