HubSpot integration deadlines: 26 Oct, 31 Oct and 4 Dec
Classic CRM cards sunset on 31 October and the Pipelines API v1 stops responding on 4 December. Existing private apps keep running until September 2027, but you can no longer create new ones from 26 October.
On 15 September 2026 HubSpot announced the end of support for its v1 to v3 APIs and its legacy apps, with enforcement in September 2027. Three nearer dates sit inside that change, and they hit this quarter: from 26 October 2026 you can no longer create a legacy private app in an existing HubSpot account, 31 October 2026 is the sunset date for classic CRM cards, and on 4 December 2026 the Pipelines API v1 stops responding.
If your business runs any custom HubSpot integration, such as an ERP sync, a private app a previous agency built, or a custom card on the contact or company record, at least one of these probably touches you. Existing legacy private apps are not switched off on 26 October. HubSpot's changelog only stops new ones being created, its documentation says legacy apps are still supported, and existing ones have until September 2027 to move to the new app model.
What to do this week: list every app connected to your HubSpot account, find out which ones are custom, and ask whoever built them two questions. Does it show a card on a record, and does it read or change pipelines? Anything that answers yes needs work before 31 October or 4 December. Everything else goes on a plan for the first half of 2027.
What exactly changes on each date?
Here is every date from HubSpot's developer changelog, as published, at the time of writing on 20 October 2026.
| Change | Date | Who it hits | What to do |
|---|---|---|---|
| Legacy private app creation ends | 28 September 2026 for new accounts, 26 October 2026 for existing accounts | Anyone planning a new integration who expected to make a private app the old way | Build new integrations with Service Keys or a Projects-based app. Existing private apps carry on for now. |
| Classic CRM cards sunset | 31 October 2026 | Anyone with a custom card in the right sidebar of a record that shows data from another system | Rebuild it as an app card before the date, or accept it will go |
| Pipelines API v1 sunset | 4 December 2026 | Any integration that reads or edits deal or ticket pipelines through the old v1 endpoints | Move the calls to the 2026-09 version of the Pipelines API |
| v4 APIs unsupported | 30 March 2027 | Integrations calling v4 endpoints | Plan the move with the v1 to v3 work |
| v1 to v3 APIs, legacy public apps and legacy private apps unsupported | September 2027 | Most custom integrations built before mid 2026 | Move to date-based API versions and Projects-based apps |
HubSpot does not give a time zone for any of these dates. HubSpot is a US company, and Brisbane is ahead of every US time zone, so treat the business day before each date as your real deadline. 31 October 2026 is a Saturday, which makes Friday 30 October the last working day to get a card change live.
Are you affected? Where to look in HubSpot
You do not need a developer to do the first pass. You need a super admin and twenty minutes.
- Connected apps. Click the settings icon, then Integrations, then Connected Apps. This lists every marketplace app and public app installed in your account. Anything built for your business alone, or by a company you have never heard of, goes on your list.
- Legacy apps. In the main navigation, go to Development, then Legacy apps in the left sidebar. Private apps live here. Each one is an integration someone built with an access token for your account, often an ERP sync, a website form handler or a reporting export. Write down the name, what it does and who built it.
- Developer home tasks card. Since 15 September, HubSpot's developer home shows a card saying how many of your apps use APIs becoming unsupported, with a link to a migrations tab. HubSpot says this checks the calls your apps actually make, so it is the fastest honest answer you will get.
- The records themselves. Open a few company, contact and deal records and look at the right sidebar. A card showing data from another system, such as ERP balances, order history or a support count, may be a classic CRM card. Ask the builder which kind it is.
If you inherited the portal from a previous agency, the Legacy apps list is the place most likely to hold an integration nobody on the current team knows about. HubSpot's own documentation suggests rotating a private app's token every six months, so check when each one was last rotated while you are there.
What breaks on 31 October: classic CRM cards
A classic CRM card is the older type of card a developer could put in the right sidebar of a record to show data pulled from somewhere else. HubSpot stopped new ones being added on 16 June 2025 and set 31 October 2026 as the sunset date for existing cards. The replacement is app cards, which are built with React and can do more, such as buttons and forms that act on the record.
The changelog says existing cards must be migrated by 31 October. It does not spell out what a user sees on 1 November, so plan on the card not being there. If your sales team checks a customer's overdue balance on the company record before calling, find out now whether that card is classic.
The fix is a rebuild, and for one simple card it is usually days of work, not weeks. HubSpot publishes a converter example on GitHub that shows how to turn a classic card into an app card. With ten days to go, the realistic choice for a complex card is to rebuild the most important one now and tell the team where to find the data in the meantime.
Not sure which of your apps is affected?
We will go through your connected apps and legacy apps with you and tell you which dates apply.
What breaks on 4 December: the Pipelines API v1
This one is the hardest cut of the three. HubSpot's changelog says plainly that v1 Pipelines endpoints will stop responding after 4 December 2026. Any integration still calling them gets nothing back.
Pipelines are the stages your deals and tickets move through. An integration uses this API when it needs to know your stage names, for example an ERP sync that sets a deal to Closed Won when an order ships, or a quoting tool that moves a deal forward. Older integrations, especially ones written a few years ago and left alone since, are the likeliest to still be on v1.
HubSpot recommends moving to the 2026-09 version of the Pipelines API, which became generally available on 9 September 2026. For most integrations that is a change to a handful of calls plus testing. The risk is not the size of the change. It is that nobody notices until the sync fails in the first week of December, when half the team is thinking about Christmas.
Ask your developer, or whoever owns the integration, to search the code for calls to v1 pipelines endpoints and confirm in writing that none are left.
What 26 October means, and what it does not
From 26 October 2026, an existing HubSpot account can no longer create a new legacy private app. New accounts lost the option on 28 September. Your existing private apps keep running, and HubSpot's changelog gives them until September 2027 to move to Projects-based private apps.
The practical effect is on new work. If an agency or freelancer quoted you an integration built as a legacy private app, that plan no longer works after this week. HubSpot now recommends Service Keys for lightweight integrations, internal tools and AI agent integrations, and the Projects-based app model for anything bigger. Ask anyone quoting integration work which of the two they are using.
Our guide to connecting HubSpot CMS to your own APIs explains how private apps, serverless functions and secrets fit together, and our developer's guide to the HubSpot API covers objects, webhooks and authentication.
What to do this week, and what can wait until 2027
Between 21 October and 4 December there are 33 weekdays. Take out the days your developers are on other work, and the run into the Christmas shutdown, and the window is shorter than it looks. Plenty of Australian businesses slow right down or shut from mid December into January, so anything not done by early December tends to wait until February.
| When | What to do |
|---|---|
| This week | List connected apps and legacy apps. Name an owner for each. Check records for classic cards. |
| By Friday 30 October | Rebuild or retire any classic CRM card your team relies on |
| By late November | Move every v1 Pipelines call to the 2026-09 version and test it, so there is time to fix problems before 4 December |
| February to June 2027 | Plan and budget the move of each private app to the Projects-based model, and every v1 to v4 API call to date-based versions |
| Before September 2027 | Finish the migration, then remove the old private apps and their tokens |
HubSpot says not every replacement endpoint is documented yet, and that a March 2027 release will include full per-endpoint replacement documentation. That is one more reason to plan the big migration for the first half of 2027 and keep this quarter for the two hard dates.
If your integration is an ERP sync, this is also a good moment to check it still does what you need. Our post on connecting HubSpot to your ERP without a blowout covers ownership of each record and what happens when a sync fails.
Frequently asked questions
Will my existing HubSpot private app stop working on 26 October 2026? No. From 26 October existing accounts can no longer create new legacy private apps. Existing ones keep running, and HubSpot's changelog gives them until September 2027 to move to Projects-based private apps.
When do classic CRM cards stop working in HubSpot? HubSpot set 31 October 2026 as the sunset date for classic CRM cards, and existing cards must be migrated to app cards by then. That date is a Saturday, so treat Friday 30 October as the deadline.
What happens to the HubSpot Pipelines API v1 on 4 December 2026? HubSpot says v1 Pipelines endpoints will stop responding after 4 December 2026. Integrations need to move to the 2026-09 version, or any call to v1 will fail.
How do I check which apps are connected to my HubSpot account? Go to settings, then Integrations, then Connected Apps for installed apps. Private apps are under Development, then Legacy apps, and you need super admin access to see them.
When do HubSpot v1 to v3 APIs go unsupported? September 2027, alongside legacy public and private apps. The v4 APIs go unsupported earlier, on 30 March 2027.
Sources
- Legacy APIs and Apps: What's Going Unsupported and When, HubSpot Developer Changelog, for the 15 September announcement, the private app creation dates, the v4 and September 2027 dates, Service Keys and the developer home tasks card.
- Deprecating support for Classic CRM Cards, HubSpot Developer Changelog, for the 16 June 2025 and 31 October 2026 dates and app cards.
- Pipelines API V1 Sunset, HubSpot Developer Changelog, for the 4 December 2026 date and the 2026-09 version.
- Legacy private apps, HubSpot developer documentation, for where private apps live and the super admin requirement.
- Connect apps to HubSpot, HubSpot Knowledge Base, for the Connected Apps settings path.
- Legacy CRM Card Converter, HubSpot on GitHub, for the card migration example.
Want someone to go through your portal's integrations and tell you what needs doing before Christmas? See our RevOps and HubSpot integration work, or talk to us.
Which of these deadlines applies to you?
Book a call and we will check your connected apps, private apps and cards with you.