A box of old backup tapes is easy to forget and quietly one of the most concentrated data risks an organisation can hold. Each tape can carry a full historical copy of your systems. They cannot simply be thrown out, and they need the right destruction method for magnetic media. This guide explains why old backup tapes matter, how to destroy them securely, and how to prove it was done.
Backup tapes are magnetic media, so they are securely destroyed either by degaussing, which uses a powerful magnetic field to render the data unrecoverable, by physical destruction such as shredding, or by both, with a certificate recording what was done. They cannot be safely thrown out, because each tape can hold a complete historical copy of your data, and simply binning them sends that data out of your control. The reason old tapes deserve particular care is that they are unusually data-dense and easy to overlook. A single backup tape is not one file; it is often a full snapshot of systems and records from a point in time, and a box of them can represent years of an organisation's complete data history. Because they sit in storage, unused, they slip out of mind, yet they remain a live exposure until they are properly destroyed. Handling them through a proper tape destruction process, matched to the fact that they are magnetic media, is what closes that risk.
Backup tapes have a way of accumulating. Superseded by newer backups or by a move to disk and cloud, the old tapes get boxed up and stored, and there they sit, out of sight and out of mind, still holding everything they ever backed up. That quiet box is exactly the kind of forgotten data store that turns into a breach years later. This guide is about dealing with it properly, before it becomes a problem.
A backup tape is not a single document. It is a snapshot of everything, which makes a forgotten box of them a serious exposure.
The defining feature of a backup tape is how much it holds. A tape does not contain one file or one folder; it contains a backup, which is typically a comprehensive copy of systems, databases and records as they stood at a moment in time. That means a single tape can hold an organisation's complete data set, and a box of tapes can hold years of successive snapshots. Whatever was sensitive in your live systems, personal information, financial records, client data, is present on the tapes that backed them up, in full. This concentration is what makes tapes a higher-stakes disposal than almost any individual device.
Compounding the risk is how easily tapes are forgotten. Because they are backups, they are meant to sit unused, and once they are superseded they are boxed and stored rather than actively managed. Organisations that have long since moved to disk-based or cloud backup frequently still have old tapes in a cupboard, a store room or off-site storage, holding data nobody is thinking about but that remains fully intact. A forgotten box of tapes is a complete historical copy of your data sitting outside your active controls, and it stays a live exposure for as long as it exists. The fact that they are old and unused does not reduce the risk; if anything it increases it, because the data on them is unmonitored. Destroying them properly is the only way to close that exposure for good.
An old backup tape is not a low risk because it is no longer in use; it is a high risk precisely because it holds a full copy of data and has dropped out of active management. The forgotten box in the store room is one of the most concentrated data exposures many organisations have, and it stays that way until the tapes are destroyed.
Tapes are magnetic media, so they need the right method. Four steps take a forgotten box to certified destruction.
Collect all the tapes together, including any in off-site storage, and account for them under a documented chain of custody, so the whole batch is tracked from the moment it is collected.
Because tapes store data magnetically, degaussing uses a powerful magnetic field to render the data unrecoverable, an effective method for this kind of media, unlike for solid-state drives.
Physical destruction such as shredding breaks the tapes down so they cannot be reused or read, often combined with degaussing for a belt-and-braces result. Our methods comparison covers how these fit together.
The destruction is recorded with a certificate, so there is evidence the tapes and the data on them were destroyed to standard, which matters given how much each tape held.
Because tapes are so data-dense, destroying them properly and keeping the certificate is worth doing deliberately rather than letting the box linger. A tape destruction service handles the magnetic media correctly and gives you the evidence. Talk to our team about clearing your old tapes.
Why a box of old tapes is not clutter but a concentrated copy of your data history.
The tapes you have stopped thinking about are the ones holding the most, outside your active controls. Figures from a named source.
There is a particular danger in data you have stopped thinking about. Live systems are monitored, access-controlled and eventually decommissioned with care; a box of old backup tapes in a store room is none of those things, yet it can hold a more complete copy of your data than any single live device. That combination, maximum data density and minimum active oversight, is exactly what makes forgotten tapes so risky, and why they surface in breach stories as the archive nobody remembered. The remedy is not complicated, but it does have to be deliberate: gather the tapes, including any in off-site storage, destroy them by degaussing and physical destruction appropriate to magnetic media, and keep the certificate as evidence. Against a maximum privacy penalty of $50M or more, and given that each tape can carry a full historical snapshot of your organisation, taking the forgotten box seriously enough to have it properly destroyed is one of the higher-value disposal decisions you can make. The tapes stop being a risk only when they no longer exist.
The questions organisations ask most about getting rid of old backup tapes.
No. Each tape can hold a complete backup, a full historical copy of your systems and records, so binning them sends a concentrated set of your data out of your control, where it could be read by anyone who obtains the tapes. Old tapes have to be securely destroyed, not discarded, precisely because of how much each one holds. The fact that they are no longer in use does not make the data on them any less sensitive.
Because tapes are magnetic media, they are destroyed by degaussing, which uses a powerful magnetic field to render the data unrecoverable, by physical destruction such as shredding, or by both for added assurance, with a certificate recording what was done. Degaussing is effective on tapes precisely because they store data magnetically, and combining it with physical destruction ensures the tapes cannot be reused or read.
Yes. Tapes store data magnetically, so a powerful magnetic field disrupts that storage and renders the data unrecoverable, which makes degaussing a genuinely effective method for tapes. This is different from solid-state drives, where degaussing does not work because they store data electronically rather than magnetically. For magnetic media like tapes and traditional hard drives, degaussing remains a sound choice, often alongside physical destruction.
They count too, and they are often the most forgotten. Tapes held in off-site or third-party storage still hold your data and remain your responsibility, so a proper disposal gathers them in as well rather than dealing only with what is on your premises. Accounting for all the tapes, wherever they are held, under a chain of custody, is part of closing the exposure completely rather than leaving a forgotten set behind.
Yes. The destruction is documented with a certificate recording that the tapes were destroyed to standard, ideally under a chain of custody from collection. Given how much data each tape held, this evidence matters: it demonstrates that a concentrated set of your data was properly destroyed if the question is ever raised. The certificate is the record that the forgotten box has genuinely and provably been dealt with.
Very much so. Moving to cloud or disk backup does not remove the data from the old tapes; it just means they stopped being used. Those tapes still hold everything they ever backed up, so a box of them left over from a previous backup regime is a live exposure regardless of what you use now. Organisations that switched backup methods years ago often still have tapes that ought to be destroyed, and doing so closes a risk that has simply been sitting quietly.
See how ITC destroys old backup tapes as magnetic media, by degaussing and physical destruction, accounting for every tape under chain of custody and providing a certificate for the batch.
Destroy it properly
Knowing the right method is only half of it. The other half is being able to prove what happened to each serial number. ITC works to the NIST 800-88 standard under ISO/IEC 27001:2022, records chain of custody from your desk to the shredder, and issues a Certificate of Data Destruction listing the devices processed.
