Backup for Accounting firms

Why Accounting firms are extra vulnerable to data loss

What makes accounting firms data a high-value target — and what happens when it's gone

Accounting firms store some of the most sensitive data in their field — including annual accounts | tax filings | client financial records. This combination of confidential records, long statutory retention obligations, and day-to-day reliance on software like Exact makes them a prime target for cybercriminals.

Ransomware groups increasingly target organisations that cannot afford downtime — and accounting firms fit that profile exactly. A firm that loses access to its annual accounts cannot operate. Deadlines are missed, regulatory obligations are breached, and clients lose trust. Under GDPR / AVG, data must be retained for 7 years — meaning a data loss event does not just disrupt operations today, it creates legal liability that extends years into the future.

The risk is not abstract. Loss of client financial records, ransomware during tax season, regulatory non-compliance on data retention is the leading threat for this sector. Files with characteristics like structured financial databases | audit trail archives are difficult or impossible to reconstruct from memory once lost. Every day without a verified, offsite backup is a day of unnecessary exposure.

• Accounting firms
• Annual accounts
• ISO 27001

The misconception that costs many accounting firms dearly

"Our accounting software is cloud-based and secure — no additional backup needed."

It is easy to understand why many accounting firms believe this. Exact is marketed as a professional-grade platform, and vendors naturally emphasise uptime and reliability. But there is a critical difference between redundancy and recovery. A system can be highly available and still offer you zero protection the moment ransomware encrypts your files or an administrator accidentally deletes a directory.

Synchronisation tools — including those built into Exact — propagate changes in near real-time. When ransomware encrypts a file, that encrypted version immediately overwrites your 'backed up' copy. By the time the attack is discovered, every sync destination contains the same unusable data. This is not a backup. It is a perfectly synchronised disaster.

The practical consequence: without an independent, immutable backup, accounting firms facing a ransomware attack have two options — pay the ransom or start over. Neither is acceptable when GDPR / AVG requires you to demonstrate full data integrity to regulators.

What do I need to back up if I use Exact?

The data accounting firms typically overlook when using Exact

Exact manages your day-to-day workflow, but its built-in data protection typically covers only what happens within the application itself. It does not automatically back up your entire data environment — and there are several categories of data that fall outside its scope entirely.

For accounting firms using Exact, the following should be included in any proper backup: annual accounts, tax filings, client financial records, audit reports. If you also use AFAS, any data in those systems must be covered separately.

Pay particular attention to structured financial databases | audit trail archives. These file types are either difficult to reconstruct or subject to strict legal retention requirements. A backup strategy that does not explicitly cover them is incomplete — and potentially non-compliant.

• Accounting firms
• Annual accounts
• Exact

What a proper backup actually does

The 3-2-1 rule — and why it matters for accounting firms

The 3-2-1 rule is the baseline standard for data resilience: keep at least 3 copies of your data, on 2 different types of storage media, with 1 copy stored offsite. For accounting firms, this is not just best practice — it is increasingly a regulatory expectation under frameworks like GDPR / AVG.

In practice: your primary production data counts as copy 1. A local backup (on a NAS or secondary server) is copy 2, enabling fast recovery without waiting for a cloud download. Copy 3 is stored in an offsite data centre — physically and logically separated from your main environment, so a fire, flood, or ransomware attack cannot reach all three copies simultaneously.

Mindtime extends this to a 4-copy model, with an additional snapshot stored in a second Dutch data centre. For accounting firms managing annual accounts, this means your data is always recoverable — from a clean, pre-attack restore point — regardless of what happens on-site.

How do accounting firms protect themselves against ransomware?

Specific measures for accounting firms — beyond antivirus

Ransomware attacks on accounting firms typically follow a predictable pattern: initial access via a phishing email or compromised credential, lateral movement to identify high-value data, and then encryption of everything — including network shares and connected backup drives.

The single most effective defensive measure is an immutable offsite backup — one that ransomware cannot reach. Beyond backup, accounting firms should implement: multi-factor authentication on all systems (particularly Exact), regular software updates and patch management, network segmentation to limit lateral movement, and staff awareness training on phishing recognitions.

Critically, a backup is only useful if it has been tested. Many organisations discover during a recovery that their backup is incomplete, out of date, or corrupted. Mindtime performs automated integrity checks on every backup and alerts you if a backup fails — so you know your data is recoverable before you need it, not during a crisis.

How do I create a backup if I use Exact?

A practical guide for accounting firms using Exact

Setting up a proper backup for accounting firms using Exact (and AFAS if applicable) involves more than activating the export function in your software. Here is the practical approach:

First, identify all data that must be retained under GDPR / AVG — including annual accounts | tax filings | client financial records. Map every location where this data lives: within Exact, on local drives, on shared network folders, and in any integrated third-party tools.

Second, configure Mindtime's agent on each endpoint and server that holds accounting firms data. The agent performs incremental backups continuously, so you are never more than a few minutes behind your last recovery point. Backup frequency, retention periods, and encryption settings are all configured to meet your specific regulatory requirements.

Third, run a test restore within the first week. Verify that annual accounts and other critical data types can be recovered fully and within your acceptable downtime window. Document the process so your team knows exactly what to do if an incident occurs.

Data retention and compliance obligations for accounting firms

GDPR / AVG and what it means for your backup strategy

Accounting firms operate under some of the most specific data retention obligations in their field. The primary framework is GDPR / AVG, which sets clear requirements for how long annual accounts must be kept, in what format, and with what level of accessibility.

Key retention requirements for accounting firms:

— 7 years (fiscal minimum)

— 10 years for audit files (Wta)

Beyond retention duration, these regulations also require that data remains accessible and verifiable throughout the retention period. A backup that cannot be searched, exported, or audited does not satisfy the requirement. Mindtime's backup platform includes point-in-time restore, meaning you can retrieve any version of a file at any point within the retention window — exactly what regulators require during an audit.

Certification under ISO 27001 demonstrates that your data protection processes meet a recognised standard — which regulators and clients increasingly expect.

• Accounting firms
• GDPR / AVG
• ISO 27001

Five steps to get this sorted

A practical checklist for accounting firms implementing a proper backup strategy

Your questions answered

Frequently asked questions about backup for accounting firms