Most offices that ran a server before cloud backup took over still have a box of backup tapes somewhere: in a comms cupboard, a fire safe, a manager's drawer or an offsite storage contract nobody has reviewed for years. Those cartridges are easy to forget because nothing reads them any more, but each one can hold a complete copy of your file server, mailboxes or accounts database from the day it was written. This guide explains how to deal with them properly.
Why old tapes matter more than old laptops
A single laptop holds one person's work. A backup tape was designed to hold everything: full copies of shared drives, email stores, HR folders, payroll and customer records, often including data that has since been deleted from your live systems. Older rotation schemes also mean there may be dozens of cartridges, each a snapshot from a different week or month.
Under UK GDPR and the Data Protection Act 2018, personal data should not be kept for longer than you need it, and it must be kept secure for as long as you hold it. Personal data on a tape you no longer use is still personal data you are responsible for. If a box of unlabelled cartridges goes missing in an office move, you may not even be able to say what was on it.
Step 1: find and count every cartridge
Before anything leaves the building, build a simple list. Check the obvious places and the less obvious ones:
- the server room or comms cupboard, including drawers under the rack;
- fire safes and locked cabinets, which were the usual home for weekly or monthly tapes;
- staff who took tapes home as an "offsite copy" in the years before cloud backup;
- any offsite storage or archive contract, which may still be holding boxes of tapes in your name;
- old tape drives and autoloaders, which can still have cartridges inside the magazine.
Most data cartridges (LTO, DLT and similar) carry a barcode label with a unique volume number. Record it, along with the format and any handwritten date or set name. That list is what you will later check against the destruction certificate, so it is worth getting right.
Step 2: decide whether anything must be kept
Do this before destruction, not after. Talk to whoever owns your records retention schedule (often finance, HR or a compliance lead) and ask:
- Is any of this data still within a retention period? Some financial and employment records have to be kept for a set number of years. If the only surviving copy is on tape, you may need to restore it to a current system first.
- Is anything subject to a legal hold? If there is an ongoing dispute, claim, investigation or regulatory request, relevant records must not be destroyed. Check with your legal adviser if in doubt.
- Can you actually read the tapes? Restoring old tapes needs a compatible drive and the original backup software. If you no longer have either, factor that into the decision rather than keeping tapes "just in case" that nobody could restore anyway.
Write the outcome down. A short note saying which tapes were reviewed, who approved destruction and why shows that the decision was deliberate, which is what the storage limitation principle expects.
Step 3: don't rely on encryption alone
Many modern tape systems support encryption (LTO drives have offered it in hardware since LTO-4), and some backup software encrypted data before writing it. It is tempting to treat those tapes as safe because the keys are long gone. In practice you often cannot prove that: older sets may have been written without encryption, keys may still exist in an old backup server or key manager, and the cartridge labels rarely say which tapes were encrypted. Treat every tape as readable and destroy it physically.
Step 4: choose the right destruction method
Tape is magnetic media, so there are two sound options, often used together:
- Degaussing applies a strong magnetic field that scrambles the recorded data. The degausser must be rated for the type of tape: newer, higher-capacity cartridges use media that needs a stronger field than older formats. On LTO cartridges, degaussing also wipes the factory-written servo tracks, so the tape can never be reused.
- Shredding cuts the cartridge and the tape inside it into small pieces, which gives visible proof that the media no longer exists.
What doesn't work: bulk-erasing in the drive, overwriting with a new backup, cutting the tape with scissors or throwing cartridges in general waste or a WEEE skip. Pulling the tape out of the shell does not remove the data from it. Our guide to wiping, degaussing and shredding explains the difference between methods across other media too.
Step 5: keep custody until the end
Tapes should go from your locked storage into a sealed, counted container, collected by a named provider and destroyed using government-approved methods. Afterwards you should receive a certificate of destruction. For tapes, ask for it to list the barcode volume numbers, or at minimum the exact count by format, so you can reconcile it line by line against your inventory from step 1. Our article on what a certificate of destruction should include covers what to check.
If an offsite storage company holds tapes for you, ask them for their own list of your boxes before you instruct destruction, and make sure the numbers match yours.
Don't forget the drives and servers
A tape clear-out usually happens when an old backup server or tape library is finally decommissioned. Those machines have their own hard drives, which may hold backup catalogues, staged backup copies and server data, and autoloaders can still have tapes loaded. Include them in the same inventory and destruction run so nothing is left behind.
Book a collection
Data Destruction London collects backup tapes, hard drives and other media from businesses across London, destroys them using government-approved methods and issues a certificate of destruction. We are registered with the ICO (ZA060744). Call 020 7064 4996 or book a collection online.