If you are running a HubSpot legacy sandbox, your time is running out. HubSpot has announced that legacy sandbox environments will be fully retired in March 2026, and any assets, configurations, or test data living exclusively in a legacy sandbox will be gone unless you migrate them before the cutoff.
Legacy sandboxes will be fully decommissioned in March 2026. All data, configurations, and assets in legacy sandboxes will be permanently deleted. There is no extension or grace period being offered. If you have not migrated by the deadline, you lose everything in the legacy sandbox.
This is not a theoretical risk. We have spoken with dozens of HubSpot teams who have critical workflow prototypes, integration test configurations, and custom property schemas that exist only in their legacy sandbox. If they do not act before the sunset date, that work disappears.
This guide walks you through exactly what is changing, what you need to back up, and how to execute the migration to HubSpot’s new sandbox framework as efficiently as possible.
What Is Changing and Why
HubSpot introduced its legacy sandbox environment as a testing ground for portal configurations. It allowed teams to prototype workflows, test integrations, and experiment with CRM architecture without risking their production data.
The Legacy Sandbox Limitations
The legacy sandbox had significant limitations that prompted HubSpot to rethink the approach entirely.
| Capability | Legacy Sandbox | New Sandbox |
|---|---|---|
| Sync direction | One-way snapshot from production | Bidirectional asset syncing |
| Data freshness | Data aged quickly and diverged | Better data refresh capabilities |
| Promote to production | No native mechanism | Push specific assets to production |
| User permissions | Not mirrored from production | Permission mirroring supported |
| Third-party integrations | Limited connectivity | Full API access |
| Sandbox types | Single type only | Development + Standard (UAT) |
The New Sandbox Environment
HubSpot’s new sandbox framework addresses most of the legacy limitations with two distinct sandbox types.
- Designed for building and testing
- Ideal for workflow prototyping
- Full API access for integration testing
- Push tested assets to production
- Designed for UAT and staging
- Mirrors production permissions
- Better data refresh from production
- Closer to production environment for realistic testing
The Sunset Timeline
January 2026: Read-Only Mode
Legacy sandboxes entered read-only mode for new asset creation. You can still view and export existing assets but cannot create new ones.
March 2026: Full Decommission
Legacy sandboxes are fully decommissioned. All data, configurations, and assets in legacy sandboxes are permanently deleted with no recovery option.
Assessing What Lives in Your Legacy Sandbox
Before you start migrating, you need a comprehensive inventory of what exists in your legacy sandbox and whether any of it is worth preserving.
Assets Worth Migrating
Focus on assets that represent real work and intellectual property.
Workflow Prototypes
Automations that were built and tested in the sandbox but never promoted to production. These represent hours of design and testing work.
Custom Property Schemas
Properties and property groups created for testing that you plan to use in production. Includes dropdown options and calculated formulas.
Pipeline Configurations
Custom deal, ticket, or object pipelines designed in the sandbox. Stage definitions and automation triggers are included.
Integration Configurations
API connections, webhook configurations, and custom code actions that were validated in the sandbox environment.
Email Templates
Marketing and sales email templates drafted or tested in the sandbox. Includes personalization token configurations.
Reports and Dashboards
Custom reports that took significant effort to build. Include filter configurations, grouping logic, and chart settings.
Assets You Can Skip
- ✗Test contacts and company records with fake data
- ✗One-off workflow experiments that never went anywhere
- ✗Duplicate templates that already exist in production
- ✗Historical test data that has no ongoing value
How to Audit Your Sandbox
Audit Workflows
Go to Automation > Workflows and list every workflow with its status, purpose, and whether an equivalent exists in production.
Audit Properties
Check Settings > Properties for any custom properties not present in production. Note data types, groups, and dropdown option values.
Review Email Templates
Check the email template library for unique templates. Export HTML source for any you need to preserve.
Check Integrations
Review Connected Apps for integrations that may need reconfiguration in the new environment.
Review Reports and Custom Objects
Document custom reports, dashboards, and any Custom Objects created for testing that have ongoing value.
For a structured approach to this audit, our portal audit checklist covers every area you need to review.
Backing Up Your Legacy Sandbox
Before you begin the migration, back up everything. Even if you do not plan to migrate every asset, having a backup means you can reference your work later.
Export Workflow Configurations
HubSpot does not offer a native workflow export feature. You need to document each workflow manually or use a tool to capture the configuration. Screenshot each workflow's visual builder, document enrollment triggers, record all internal notifications, and note connected assets.
For teams with dozens of workflows, this manual process is where Jetstack’s asset copying tools can save days of tedious documentation work. Our tools extract workflow configurations programmatically and output them in a structured format you can use for recreation.
Export Property Schemas
Go to Settings > Properties and export your custom properties. HubSpot allows you to export properties as a CSV.
- ✓Property name and internal name
- ✓Property type (text, number, dropdown, etc.)
- ✓Property group assignment
- ✓Dropdown option values (for enumeration properties)
- ✓Calculated property formulas (document manually — not included in CSV export)
Export Email Templates and Content
For marketing emails, export the HTML source from each template. For sales templates, copy the body text and note any personalization tokens used. For details on the email migration process, see our email template transfer guide.
Export Reports, Dashboards, and Integrations
HubSpot does not support direct export of report configurations. Screenshot each report's settings panel, noting report type, data sources, filters, grouping, date range, and chart type. For integrations, record API endpoints, authentication methods, webhook URLs, custom code actions, and scopes.
Migration to the New Sandbox Environment
With your backup complete, it is time to move assets to HubSpot’s new sandbox.
Setting Up the New Sandbox
Create the New Sandbox
Navigate to Settings > Account Defaults > Sandboxes, select "Create Sandbox," and choose the type (Development or Standard).
Choose Initial Sync Assets
Select which production assets to include in the initial sync. The new sandbox will be seeded with a copy of your production portal's configuration.
Focus on the Delta
Many properties, pipelines, and settings already exist from the production sync. Your migration work focuses on the delta — assets that exist only in the legacy sandbox.
Migrating Workflows
Workflow migration is the most complex part of this process.
Check for Production Equivalents
For each workflow documented from the legacy sandbox, check whether an equivalent already exists in the new sandbox (inherited from production).
Recreate Missing Workflows
If no equivalent exists, recreate the workflow in the new sandbox using your documentation. Follow the original design exactly.
Rebuild Enrollment Triggers
Ensure any referenced lists, forms, or properties exist in the new sandbox before configuring triggers.
Reconnect Dependent Assets
Reconnect emails, tasks, and internal notifications. Verify that every dependent asset is available in the new environment.
Test with Sample Records
Test the workflow with sample records before relying on it. Verify every branch, delay, and action step executes correctly.
For a detailed walkthrough, our workflow migration checklist covers every step and common failure point.
Migrating Custom Properties
For properties that exist in the legacy sandbox but not in production (and therefore not in the new sandbox):
- ✓Review each property and confirm it is still needed
- ✓Create the property in the new sandbox with identical settings
- ✓Match internal property names exactly (workflows and integrations reference these)
- ✓Recreate calculated property formulas manually
- ✗Do not assume property IDs will match — they never do between environments
Migrating Email Templates and Integrations
For email templates that exist only in the legacy sandbox, export the HTML source, recreate the template in the new sandbox’s design manager or email editor, update any image URLs that reference the legacy sandbox’s file manager, and verify personalization tokens work with the new sandbox’s property schema.
Integrations often involve third-party credentials and endpoint configurations. Reconnect each app using the same credentials (or sandbox-specific credentials), reconfigure webhook endpoints to point to the new sandbox URLs, recreate custom code actions from your backup, and test each integration end-to-end with sample data.
Testing Checklist for the New Sandbox
Once your assets are migrated, validate everything works correctly in the new environment before the legacy sandbox goes away.
Workflow Testing
For each migrated workflow, verify: enrollment trigger fires correctly, each action step executes as expected, branch logic routes records correctly, delay timers are configured with correct durations, connected emails render correctly with personalization tokens, goal criteria are set and trackable, and re-enrollment settings match the intended behaviour.
Property Testing
For each migrated property, verify: property appears in the correct group, property type matches the original, dropdown options are complete and in the correct order, property is visible on the intended record types, and calculated properties compute correct values.
Integration Testing
For each reconnected integration, verify: authentication is valid and the connection is active, data syncs bidirectionally (if applicable), webhook payloads are received and processed correctly, custom code actions execute without errors, and error handling and retry logic function as expected.
Email Testing
For each migrated email template, verify: template renders correctly in the email editor, personalization tokens populate with test data, images and links are not broken, mobile responsive layout works, and test send reaches inbox (not spam).
Accelerating the Migration with Jetstack
The manual process described above works, but it is time-consuming. For teams with more than a handful of workflows and properties to migrate, the manual approach may not be feasible before the March deadline.
Where Jetstack Helps
Jetstack’s platform is built specifically for scenarios like this: moving HubSpot assets between environments quickly and reliably.
Asset Discovery
Instead of manually walking through every section of your legacy sandbox, Jetstack scans the portal and produces a structured inventory of all assets, their dependencies, and configuration details.
Workflow Replication
Rather than manually recreating each workflow step by step, Jetstack extracts configurations and helps rebuild them with correct triggers, actions, and dependencies intact.
Property Schema Transfer
Jetstack maps property schemas between portals and identifies discrepancies, so you know exactly which properties need to be created and which already exist.
Dependency Mapping
Maps which workflows depend on which lists, which lists depend on which properties, and which emails are triggered by which workflows — automatically. See our workflow dependencies guide.
Timeline: Jetstack vs. Manual
- 2-4 weeks of focused work
- Requires deep HubSpot expertise
- High risk of missed dependencies
- Documentation is manual and error-prone
- Testing must be done asset-by-asset
- 3-5 days including testing
- Automated asset discovery and documentation
- Dependencies mapped automatically
- Structured output for recreation
- Validation tooling catches errors early
Given that the legacy sandbox sunset is in March 2026, teams who have not started yet need to move quickly. The Jetstack implementation team can scope your migration and provide a timeline within 24 hours.
What Happens If You Miss the Deadline
If you do not migrate your legacy sandbox assets before March 2026, they are gone. HubSpot has been clear that decommissioned legacy sandboxes will not be recoverable. There is no backup, no grace period, and no support ticket that will restore your data.
The Real-World Impact
Workflow Prototypes
Automations you spent weeks building will need to be recreated from memory. Without documentation, the nuanced branch logic and trigger configurations are likely to be rebuilt incorrectly.
Integration Configurations
API connections that took trial and error to get right will need to be rebuilt. Authentication flows, webhook configurations, and custom code actions are especially painful to recreate without references.
Property Schemas and Email Templates
Properties designed for future projects will need to be re-architected. Email templates tested and refined in the sandbox will need to be redesigned from scratch.
Last-Resort Actions
If you cannot complete a full migration before the deadline, prioritise these actions:
Export Everything as Documentation
Screenshots, CSVs, code copies — capture everything you can in a format you can reference later, even if you cannot recreate it in time.
Focus on High-Value Workflows
Prioritise workflows that represent the most significant investment of time and expertise. These are the hardest to recreate from memory.
Back Up Custom Code Verbatim
Copy every custom code action word-for-word. Code is the single hardest asset type to recreate from memory, and losing it means starting from zero.
Document Integration Configurations
Record API keys, endpoints, webhook URLs, and scopes. Even with documentation, rebuilding integrations takes time — without it, the process takes far longer.
Even if you cannot recreate everything in the new sandbox before March, having comprehensive documentation means you can rebuild later without starting from scratch.
Planning Your Migration Timeline
Here is a realistic timeline for completing the migration before the March 2026 deadline.
| Week | Phase | Key Activities | Deliverable |
|---|---|---|---|
| Week 1 | Audit and Inventory | Full sandbox audit, categorise assets (must migrate / nice to have / skip), identify dependencies, set up new sandbox | Prioritised asset inventory |
| Week 2 | Backup and Documentation | Export all asset configurations, document workflow logic, property schemas, integration settings | Complete backup archive |
| Week 3 | Migration Execution | Recreate high-priority assets, migrate properties → lists → workflows (dependency order), reconnect integrations | Assets live in new sandbox |
| Week 4 | Testing and Validation | Run testing checklist for every asset, fix issues, confirm production unaffected, decommission legacy reliance | Validated new sandbox environment |
For teams starting this process now (February 2026), you are cutting it close. A four-week timeline requires focused, dedicated effort. If your legacy sandbox has more than 30 workflows or complex integrations, consider engaging the Jetstack team for accelerated migration support.
FAQ
When exactly are HubSpot legacy sandboxes being retired?
HubSpot has set March 2026 as the date for full decommission of legacy sandbox environments. Leading up to this, legacy sandboxes entered restricted functionality in January 2026, with new asset creation disabled. After the March deadline, all legacy sandbox data is permanently deleted.
Can I request an extension from HubSpot for the sandbox sunset?
HubSpot has not announced any extension or grace period for the legacy sandbox retirement. The company has been communicating this change since late 2025 and considers the migration path to the new sandbox environment to be the official resolution. If you are a large enterprise customer, contact your HubSpot Customer Success Manager to discuss your specific situation, but do not count on an extension.
What is the difference between the legacy sandbox and the new sandbox?
The legacy sandbox was a one-time snapshot of your production portal with limited sync capabilities. The new sandbox framework offers two types: Development sandboxes for building and testing, and Standard sandboxes for UAT. The new sandboxes support asset syncing to production, better data refresh, full API access for integrations, and user permission mirroring.
Will my production portal be affected by the legacy sandbox sunset?
No. The legacy sandbox retirement only affects assets stored in the legacy sandbox environment. Your production portal, its data, workflows, and configurations are completely unaffected. The risk is only to assets that exist exclusively in the legacy sandbox and have not been replicated in production or the new sandbox.
Can I migrate directly from the legacy sandbox to production instead of the new sandbox?
Yes, if the assets in your legacy sandbox are ready for production use, you can recreate them directly in your production portal. However, we recommend using the new sandbox as an intermediate step so you can test everything before it goes live. Pushing untested sandbox prototypes directly to production introduces risk to your live operations.
How do I know if I am using a legacy sandbox?
Check your portal settings under Account Defaults > Sandboxes. If your sandbox was created before HubSpot introduced the new sandbox framework, it is a legacy sandbox. HubSpot has also been sending email notifications to portal administrators about the upcoming retirement. If you received these notifications, you have a legacy sandbox that needs attention.
What if I have assets in the legacy sandbox that I no longer need?
If your legacy sandbox contains only test data and experimental configurations that are no longer relevant, you do not need to do anything. The sandbox will be decommissioned and the assets deleted. The only action required is to confirm that nothing valuable exists exclusively in the legacy sandbox. Run a quick audit to verify, and document your confirmation so your team has a record.