The Risks of Relying on Sync Services as Backup

There is a dangerous misconception spreading through UK businesses of all sizes: the belief that cloud sync services like OneDrive, Google Drive, and Dropbox are adequate substitutes for proper backup. It is easy to see why this confusion exists — these services store copies of your files in the cloud, so surely they protect against data loss? Unfortunately, the reality is far more nuanced, and businesses that rely solely on sync services for data protection are taking risks they may not fully understand.

Sync services and backup solutions serve fundamentally different purposes, and understanding the distinction could save your business from a catastrophic data loss event. This is not a theoretical risk — UK businesses lose critical data every day because they assumed their sync service had them covered, only to discover too late that it did not.

This guide explains the critical differences between sync and backup, the specific risks of relying on sync services alone, and what a proper backup strategy looks like for UK businesses in 2025.

Sync vs Backup: The Critical Difference

At its core, the difference between sync and backup comes down to intent and behaviour. A sync service is designed to keep files consistent across multiple devices and locations in real time. When you edit a document on your laptop, the change is immediately replicated to the cloud and to any other device linked to your account. A backup solution is designed to create point-in-time copies of your data that can be restored if the originals are lost, corrupted, or compromised.

The critical implication of this difference is that sync replicates everything — including mistakes, deletions, and corruption. If you accidentally delete a folder from your synced OneDrive, that deletion is immediately synced to the cloud and every linked device. If a ransomware virus encrypts your files, those encrypted files are synced to the cloud, potentially overwriting the good copies. If a staff member maliciously or accidentally modifies a database, those changes propagate instantly.

A proper backup, by contrast, maintains independent copies of your data at specific points in time. If today's data is corrupted, you can restore yesterday's backup. If last week's data was better, you can go back to that point. The backup exists independently of your live data, so problems that affect your live environment do not automatically affect your backups.

Risk 1: Ransomware and Malware Propagation

Ransomware is the most pressing cyber threat facing UK businesses, and it is the scenario where the sync-versus-backup distinction matters most. When ransomware encrypts files on a synced device, the sync client faithfully uploads the encrypted versions to the cloud, overwriting the clean copies. By the time the attack is discovered, the encrypted files have propagated to every connected device and the cloud storage.

While services like OneDrive and SharePoint do offer version history that can theoretically allow you to roll back to pre-encryption versions, this process has significant limitations. First, rolling back thousands of files individually through version history is extraordinarily time-consuming — for a business with 50,000 files, this could take days of manual work. Second, version history has a limited depth, and if the attack is not detected quickly, older clean versions may have already been purged. Third, ransomware variants are increasingly designed to target and corrupt sync service version histories specifically.

A proper backup solution, particularly one using the 3-2-1 backup strategy (three copies of your data, on two different media types, with one copy off-site), provides a clean, isolated copy that ransomware cannot reach. If your live data and sync service are both compromised, you can restore from backup with confidence.

Risk 2: Accidental Deletion Beyond Recovery Windows

Every sync service has a recycle bin or trash folder where deleted files are temporarily retained. OneDrive retains deleted files for 93 days. Google Drive retains them for 30 days. Dropbox Business retains them for 180 days. After these retention periods, deleted files are permanently gone.

For many UK businesses, 30 or even 93 days is not enough. Consider a scenario where a staff member accidentally deletes a folder of client contracts. If the deletion is not noticed for four months — perhaps the contracts are only referenced annually — the OneDrive recycle bin retention has expired, and the files are unrecoverable. With a proper backup solution configured with 12-month retention, those contracts could be restored easily.

The risk is compounded when staff leave the organisation. When a Microsoft 365 licence is removed from a departed employee's account, their OneDrive data is retained for a limited period (configurable, but often defaulting to 30 days) before being permanently deleted. If nobody thinks to preserve or transfer that data within the retention window, years of work could be lost forever.

Risk 3: Scope Limitations

Sync services only protect files that are stored within their designated folders. OneDrive syncs files in the OneDrive folder. Google Drive syncs files in Google Drive. But your business data extends far beyond these folders.

What about your accounting software database? Your CRM system data? Email archives? Server configurations? Application settings? Browser bookmarks and saved passwords? Registry settings? These critical data sources exist outside sync service folders and receive no protection whatsoever from sync-based approaches.

A comprehensive backup solution captures everything — entire system images, databases, application data, email archives, and configuration files. If a server fails catastrophically, a proper backup allows you to restore the entire machine to a new server, complete with all software, settings, and data, in hours rather than days or weeks of manual reconstruction.

Risk 4: Compliance and Legal Requirements

UK businesses face regulatory requirements around data retention and recovery that sync services alone cannot satisfy. GDPR requires that personal data can be recovered in a timely manner in the event of a physical or technical incident (Article 32). Various industry regulations impose specific data retention periods — financial services firms must retain certain records for seven years, for example.

Sync services offer limited control over retention policies, and their terms of service can change at any time. A sync provider could reduce retention periods, change pricing, or even cease operations entirely, leaving your compliance posture exposed. With a proper backup solution, you control the retention policies, the storage locations, and the recovery procedures, ensuring ongoing compliance regardless of what happens with third-party services.

Building a Proper Backup Strategy

Understanding the risks of sync-only approaches is the first step. The next step is implementing a proper backup strategy that provides genuine protection for your business data.

Start with a data audit. Identify every source of business-critical data — files, databases, email, applications, cloud services, and system configurations. Document where each data source lives, how important it is to your business, and how much data loss you can tolerate (your Recovery Point Objective, or RPO).

Implement the 3-2-1 strategy. Your primary data lives on your production systems. A local backup (on a NAS device or dedicated backup server) provides fast recovery for everyday incidents. An off-site or cloud backup provides protection against physical disasters and ransomware that might compromise both your production systems and local backups.

Test your backups regularly. A backup that has never been tested is a backup you cannot trust. Schedule quarterly restore tests where you actually recover data from your backups and verify its integrity. Document the results and the time taken — this becomes your Recovery Time Objective (RTO) benchmark.