Azure Backup Pricing UK 2026

1. Azure Backup pricing at a glance

Azure Backup has two billing dimensions: a protected instance fee charged per workload per month, and backup vault storage charged per GB per month. There is also an optional add-on for Cross-Region Restore, which requires RA-GRS vault storage. Most teams notice the per-instance fee first — it looks modest — and underestimate the storage line, which is usually the dominant cost.

Source: Azure Retail Prices API (USD-only service), converted at 0.7548 GBP/USD. Verified April 2026.

2. Why storage usually dominates the instance fee

Consider 10 Azure VMs, each with 500 GB of active data and a 30-day retention policy. The instance fees total £75.50/month — just £7.55 per VM. That looks manageable. But the backup vault storage tells a different story. Azure Backup accumulates incremental backup points throughout the retention window. Assuming a 5% daily change rate (typical for general-purpose VMs), each VM accumulates roughly 500 GB × (1 + 0.05 × 30) = 2,250 GB in the vault. Across 10 VMs that's 22,500 GB. At LRS rates: 22,500 GB × £0.0211 = £474.75/month.

The storage-to-instance ratio gets worse with longer retention and higher daily change rates (SQL Server at 10% daily change stores proportionally more). This is the headline insight for Azure Backup: plan your budget around the storage cost, not the instance fee.

3. LRS vs GRS vs ZRS vs RA-GRS — when does each make sense?

Vault storage redundancy is the highest-leverage cost control in Azure Backup. GRS doubles the storage cost compared to LRS. RA-GRS costs ~2.5×. Yet GRS is often enabled by default in ARM templates and Terraform modules without explicit intent.

4. The Cross-Region Restore surprise

Cross-Region Restore (CRR) allows you to restore backed-up data to the paired Azure region — useful if you need to recover from a full regional outage. CRR requires an RA-GRS vault. The cost has two layers that teams often miss:

1. The RA-GRS storage premium (~2.5× LRS) applies to your entire vault, not just the data you intend to restore across regions.
2. When you actually perform a cross-region restore, you pay for the data transfer out of the secondary region. This is a one-time charge per restore event and scales with the data size restored.

Most teams enable RA-GRS "because it sounds like the safe option" and then never perform a cross-region restore. The ongoing storage premium is a permanent cost for a capability that may never be exercised.

5. Retention policy and vault storage — the multiplier effect

Azure Backup's pricing model accumulates storage for each retained backup point. The longer you keep backup history, the more vault storage you consume. The formula is straightforward:

Multiplier = vault storage / active data size. A 12-month retention policy for SQL Server stores ~37× the active data size in the vault.

6. Azure Backup vs Azure Site Recovery — related but not interchangeable

Both services protect data and both have a storage-dominated cost structure. The use cases are different:

Site Recovery is more expensive because it provides continuous replication rather than periodic snapshots. For most workloads, the right architecture uses both: Backup for operational recovery (file restores, corruption) and Site Recovery for DR failover (regional outage). Building a DR business case on Backup alone will leave gaps.

7. Soft-delete and the storage tail beyond your retention policy

Soft-delete is enabled by default on Azure Recovery Services vaults since 2021. When backup data is deleted (manually or when a retention policy expires), soft-delete keeps the data for 14 additional days before permanent deletion. This adds a storage cost tail beyond your intended policy. For large vaults with high turnover — environments that frequently onboard and offboard VMs — the soft-delete tail can represent a meaningful fraction of the total vault size. It is worth knowing about when building detailed forecasts, though for most workloads it is a second-order effect.

8. Azure Files backup — the lowest-cost workload type

Azure Files backup has the lowest daily change rate assumption (2% per day) and the lowest instance fee (£4.72/month). For file share workloads that are largely static — document libraries, configuration stores, data exports — the vault storage stays manageable even with longer retention. A 10 TB Azure Files share with 90-day retention accumulates roughly 28 TB in the vault at LRS rates (£591/month total), compared to a similar SQL database which would accumulate ~100 TB. If you have a choice about where to store data that needs long-term backup, Azure Files is the cheaper backup substrate.

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