Azure Reserved Instance Flexibility Expanded — Now Exchange Any VM Size Within the Same Family Instantly

What Changed?

Microsoft expanded Azure Reserved Instance (RI) instance size flexibility to allow exchanges across all VM sizes within the same family — not just within the same size group as previously. A reservation purchased for D4s v5 (4 vCPU) can now be applied to or exchanged for any Dsv5 instance from D2s v5 (2 vCPU) to D96s v5 (96 vCPU). Additionally, the exchange processing time has been reduced from up to 24 hours to under 1 hour in most cases.

Why Does This Matter?

The previous limitation was a significant barrier to committing to Azure 3-year Reserved Instances. If your application needs grew and you needed to move from D4s to D8s, you could not apply your existing RI — it would sit unused while you paid on-demand pricing for the larger instance. This made many organisations reluctant to commit to 3-year terms. With full family-wide flexibility, that risk is eliminated. A 3-year Dsv5 RI saves 63% vs pay-as-you-go pricing — previously risky to commit to, now safe with instant resize.

The Financial Impact

Consider a team running 10× D8s v5 instances (8 vCPU/32GB): PAYG = $280/month each = $2,800/month total. 3-year RI = $104/month each = $1,040/month total. Annual saving: $21,120. Previously, many teams chose 1-year RI ($168/month, saving $1,344/month) to avoid the commitment risk. With the new flexibility, the 3-year RI becomes the clear choice — doubling the annual saving from $16,128 to $21,120 for the same 10 instances.

How to Use It

To purchase: Azure Portal → Reservations → Add → Select Virtual Machines → choose Dsv5 or your target family. Set scope to Shared (applies across all subscriptions in your billing account) for maximum flexibility. Set instance size flexibility to Enabled (this is the default for most VM families). To exchange an existing RI: go to Reservations → select the RI → Exchange → select the new size. The exchange is processed within an hour and the pricing difference is settled via credit or charge to your billing account.

Who Should Act Now

Any Azure customer running D-series, E-series, F-series, or B-series VMs on pay-as-you-go or 1-year RI pricing should re-evaluate their commitment tier. Calculate your break-even: 3-year RI is always better if you expect to run the workload for more than 20 months. Use the Azure Cost Management → Reservation Recommendations report which automatically shows your top RI purchase opportunities based on your last 30 days of usage.