Using of of B1s for the Size of a VM

Hi @Raheleh ,

please check if these VM SKUs (free) are available for you:

For Windows VM: B2ATS

For Linux VM: B2ATS, and B2PTS

All of these are free of charge (750 hours per month) if used with a P6 (64GiB) managed disk.

Source: https://marketplace.microsoft.com/en-us/product/azure-services/microsoft.freeaccountvirtualmachine?tab=overview

As the B series (version 1/v1) is being retired in a lot of Azure regions the B2ATS might be the preferred VM SKU.

More details: https://learn.microsoft.com/en-us/azure/virtual-machines/sizes/general-purpose/bsv2-series?tabs=sizebasic#sizes-in-series

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards

Andreas Baumgarten

Hello Raheleh, The Standard_B1s VM size belongs to the B-series (burstable) virtual machines. If you are seeing “Size not available” even after changing regions or security settings, this is typically due to SKU retirement, regional capacity, or subscription-level limitations, rather than any configuration issue.

As already mentioned by Andreas, the original B-series (v1) virtual machines are scheduled for retirement by November 2028. Due to this retirement plan, many regions have already restricted or removed availability of these VM sizes, especially for new deployments.

Official retirement announcement

• Retirement: The F, Fs, Fsv2, Lsv2, G, Gs, Av2, Amv2, and B series VMs are retiring in 2028
• Retired Azure VM size series

Once go to the Subscription >> Usage + Quotas >> Check for the B-series quota details.

Subscription and quota considerations

You can verify availability by navigating to: Azure Portal → Subscriptions → Usage + quotas

• If the B-series quota is unavailable, you may request access by creating a support ticket
• However, Free Trial subscriptions are not eligible for quota increase requests, which means retired or restricted SKUs such as Standard_B1s cannot be enabled in those subscriptions.

Reference: https://learn.microsoft.com/en-us/azure/quotas/per-vm-quota-requests

Microsoft recommends using the newer B-series v2 (Bsv2) VM sizes, which are actively supported and available in more regions

Reference: https://learn.microsoft.com/en-us/azure/virtual-machines/sizes/general-purpose/b-family

Hope this helps! Please let me know if you have any queries

Please do take a moment to click on "Accept Answer" button.

Source credits: https://learn.microsoft.com/en-us/answers/questions/5691425/how-to-get-b1s-size-for-a-virtual-machine-in-azure

On a free Azure account, not all VM sizes are always available in every region or for every subscription. The Standard_B1s size is a B‑series burstable VM and may be unavailable due to:

1. Regional availability or capacity
   • B‑series VMs (including Standard_B1s) are general‑purpose, burstable VMs that run on specific hardware in certain regions.
   • If the chosen region does not currently offer Standard_B1s for the subscription or capacity is exhausted, that size will not appear.
2. Quota or subscription limits
   • Even for free accounts, VM core quotas apply per region and per VM family.
   • If the B‑family quota in the selected region is 0 or already used, Standard_B1s will not be selectable.

To use Standard_B1s:

1. Try a different region
   • When creating the VM, change the region (for example, to another nearby region) and check if Standard_B1s appears in the size list.
2. Check and request quota for B‑family VMs
   • Go to the subscription’s vCPU quotas and verify that there is available quota for the B‑family in the target region.
   • If the quota is 0, submit a quota increase request for B‑series cores in that region.
3. Use another B‑series size if available
   • If Standard_B1s is not available but other B‑series sizes (for example, Standard_B1ms, Standard_B2s) are, select one of those instead. They use the same CPU credit model and are also suitable for small workloads.

Once the region and quota conditions are met, Standard_B1s will appear as an available size when creating the VM.

References:

• Bv1 sizes series
• 'B' family general purpose VM size series
• VirtualMachineSizeTypes.StandardB1s Field
• VirtualMachineSizeType.StandardB1S Property