Salesforce Spring '27 Release Dates and Test Checklist

The Salesforce Spring '27 release dates start with sandbox preview on 8 January 2027. Preview sandboxes upgrade on 8 and 9 January, and production and non-preview sandboxes upgrade on weekends in January and February 2027. Your own date depends on your instance, which you can look up on Salesforce Trust (Salesforce Help 000391927, 3 Nov 2026).

When is the Spring '27 release?

Salesforce's sandbox preview article gives the sandbox dates. Trust lists the production ones. They are in UTC on Trust, so a Friday night in California can show up as Saturday.

Salesforce's release FAQ says the gap between sandbox preview and production is four to five weeks, so use the dates for your own instance (Salesforce Help 005224913).

How do I find my instance and my upgrade date?

Four places, in the order I would use them.

1. In production, open Setup, then Company Information, and read the Instance field.
2. Open Salesforce Trust, search for the instance name and open its Maintenances tab. The Spring '27 Major Release row shows your start time. A Developer Edition org on instance USA844 shows 20 February 2027 at 05:00 UTC for Spring '27, and 12 June 2027 for Summer '27 (Salesforce Trust).
3. For sandboxes, open Setup, then Sandboxes, and read the Release Type column. It says Preview or Non-Preview.
4. Paste any sandbox instance name into Salesforce's Sandbox Preview Guide. It tells you whether that sandbox will move to Spring '27 and what to do if you want the opposite (Salesforce Help 000391927).

Production is not optional and cannot be delayed. Salesforce's FAQ says automatic upgrades are mandatory under your contract, and that they are planned for off-peak hours and weekends with no downtime (Salesforce Help 005224913).

Do I need to refresh my sandbox before the cutoff?

Usually not. Most sandboxes already sit on a preview instance, so they upgrade on their own on 8 January. Two cases need action.

If you want a sandbox on Spring '27 and it is on a non-preview instance, refresh it before the 7 January cutoff. If you want one to stay on Winter '27, refresh it after the cutoff. That keeps a stable place to build production changes. You can also ask Salesforce Support to enable the Request Non-Preview option and choose it when you refresh.

Do not leave it to the last day. Salesforce says incomplete sandboxes are reset to a non-preview instance before the preview starts, and recommends requesting at least a week before the deadline. A full sandbox copy can take a long time (Salesforce Help 000391927).

Why can't I deploy from the preview sandbox to production?

You can, until you build something in it. Production stays on Winter '27 until its weekend, and anything you create in a Spring '27 sandbox is stamped with the newer API version. Deploy that to production and you get the error The field apiVersion can't be "69" (your number will differ).

Salesforce's fix is to wait until both orgs are on the same release, or to lower the API version of the Flow or Apex class by one in the source org and upload again (Salesforce Help 005131458, 26 Jan 2026).

I keep it to one rule: test in the preview sandbox, build in one that is still on Winter '27. The change set errors guide covers the other failures you will meet while you do.

What should I test in the Spring '27 preview sandbox?

Work through this on the first Monday after 9 January, with a refreshed copy of production data if the sandbox is a full one.

1. Run all local Apex tests. Compare the pass count with a run on production the same day. A difference is a Spring '27 change or a data difference, and you want to know which.
2. Validate your next release. Run a check-only deploy of the change you plan to ship in February. Salesforce says to test all scenarios in full-copy sandbox preview instances before the production release.
3. Open your five most important flows and run each one. Use real records. Check scheduled flows and flows that fire from an integration user, since those are the ones nobody watches. Flows deploy inactive more often than people expect, so confirm which versions are active.
4. Log in as every integration user. Check Login History for failures after the upgrade. Start with the apps listed in the OAuth (open authorization) changes guide: idle refresh tokens, device-flow logins and SOAP login() callers.
5. Switch on the SOAP login() test run. In Setup, open Release Updates and enable the test run for the SOAP API login() retirement (API versions 31.0 to 64.0, Summer '27). Then run each job that signs in that way (Salesforce Help 005132110).
6. Check installed packages. Note the version of each managed package and open the vendor's release notes. Ask the vendor whether the package has been tested on Spring '27. A managed package installation cannot be rolled back, so do not skip this one (Salesforce Help 005224913).
7. Write what you find in one list, with an owner per item.

If you want a tool to do the compare in step 2, Clientell AI diffs the sandbox against production and runs a check-only deploy before anyone approves.

If a deploy fails in preview, read the deployment errors guide before you change anything.

What should I do on the production weekend?

Keep it boring. Salesforce advises you not to schedule admin-related transactions during the upgrade windows it communicates (Salesforce Help 005224913). So: no deployments, no data loads, no integration changes. Pause scheduled releases that fall on your instance's weekend.

On the Monday, run the same five flows and the integration logins again. Keep a retrieved copy of your key metadata from the Friday before so a rollback has something to start from.

Try it in Clientell AI: "Compare my full sandbox with production and list every flow and Apex class that differs, without deploying anything." Book a call with an expert, or start the 14-day trial, no card. Not ready? Run the free health check on your org. Clientell AI MCP is $249 a month and the Platform plan is $500 a month. See pricing.

Sources

Salesforce

• Salesforce Sandbox Preview Instructions, Salesforce Help 000391927, 3 Nov 2026
• Salesforce upgrade release schedule FAQ, Salesforce Help 005224913, 24 Feb 2026
• Error when deploying a change set: the field apiVersion can't be set to an unsupported version, Salesforce Help 005131458, 26 Jan 2026
• Platform SOAP API login() Retirement and new Security Requirements, Salesforce Help 005132110
• Salesforce Trust, maintenances

Last reviewed 4 November 2026