The 3-2-1 rule for backing up condominium data

What the numbers 3, 2 and 1 mean

The 3 is the minimum number of copies of the data: the working original plus two backups. Having a single spare copy is risky, because if that backup becomes corrupted exactly when you need it, nothing is left. With two backups, the odds of both failing at the same moment are very low.

The 2 refers to two different media types: for example the server's internal disk and an external drive, or a local disk and a cloud archive. Using different media protects against a failure affecting an entire technology, such as identical drives from the same batch failing at once.

The 1 is the off-site copy. A fire, a flood or a theft at the firm can destroy every copy stored in the same room. The off-site copy, in the cloud or at a second location, is what truly saves the management in the event of a disaster.

Which condominium data to protect first

Not all data carries the same weight. Priority goes to documents that cannot be reconstructed and to those the manager is required to keep and hand over: the owners' register, the register of minutes, the register of appointment and revocation, the accounting register, approved financial reports and the supporting documentation referenced by Article 1130-bis of the Italian Civil Code.

Next come supplier contracts, insurance policies, electronic invoices and tax documents such as annual tax returns, single certifications and receipts. The owners' contact and personal details also belong here, with the caveat that they are personal data governed by Regulation EU 2016/679.

• Mandatory registers and financial reports: top priority, frequent backup
• Contracts, policies and tax documents: periodic backup and long retention
• Owners' register and contacts: encrypted backup to protect personal data

Recommended media and frequency

For the local copy on different media, an encrypted external drive or a dedicated NAS work well. For the off-site copy, the cloud is the most practical choice, because it removes the physical transport of drives and replicates the data automatically. A cloud-based management system already provides a remote copy, but it does not fully replace an independent backup under the firm's direct control.

Frequency depends on how often the data changes. Active accounting and cash movements deserve a daily backup, because a lost working day is still a significant loss. Historical archives that no longer change can be copied weekly or monthly and then kept for the long term.

The most common mistake: the backup no one checks

The 3-2-1 rule fails when the copies exist but do not work. A full disk, a folder excluded by mistake, a corrupted file or a forgotten password make the backup useless at the very moment it is needed. That is why the rule must be completed with a periodic check that actually restores the data, not just verifies that it is present.

A quarterly test is enough: pick a file or a folder and attempt to restore it to a separate location, checking that the content is readable and complete. If the restore succeeds, the protection chain is healthy.

How AmministraPro helps keep data safe

With a cloud management system like AmministraPro, accounting data, documents and the owners' register are stored on secure, replicated infrastructure, so an off-site copy is guaranteed by design, reducing the firm's manual work. It remains good practice to add an independent local backup to complete the 3-2-1 rule.

You can see the archiving and retention features on the /funzioni page and compare the available plans on the /prezzi page, to choose the right setup for the size of your firm.

Frequently asked questions