Custom HubSpot API integration for the software you actually use
If your software is not listed, we can still connect it. A custom HubSpot API integration links HubSpot to the system your business runs on, through middleware we build, host and look after.
What is a custom HubSpot API integration?
A custom HubSpot API integration connects HubSpot to the software your business runs on when no ready-made connector fits, using each system’s API: the published rules that let one system read and write data in another. Big Presence builds it through middleware, a layer of code between the two systems that moves and checks the data.
- Who builds it: Big Presence, a HubSpot Platinum Solutions Partner based in Wilmslow, Cheshire.
- What it can connect: software with an API or webhooks, checked at scoping before you commit.
- Why middleware: if a platform changes its API, we update the middleware instead of rebuilding.
- Price: fixed once scoped. New scope gets a new estimate.
- After launch: we host and support it, or hand over the working code and repository.
Last reviewed
Why build a custom HubSpot API integration?
HubSpot connects to a lot of software out of the box. However, specialist platforms often miss out. That leaves you with workarounds like these:
A connector that almost fits
The ready-made app moves some fields but not the ones you report on.
Spreadsheets as the glue
Someone exports from one system every week and imports into the other.
A script nobody understands
It was written years ago. Since then, the person who wrote it has moved on.
Breaks that go unnoticed
A system updates, the link stops, and nobody finds out until a customer complains.
What data does a custom HubSpot API integration move?
Every build is designed around your process. Even so, these are the shapes most projects take.
| From | To | What moves | Direction |
|---|---|---|---|
| HubSpot | Your software | Contacts, companies or deals, when an agreed event happens in HubSpot | One way |
| Your software | HubSpot | Bookings, jobs, payments or outcomes, so reports show the full story | Back to HubSpot |
| HubSpot | Your software | Updates in either system, kept in step through the middleware | Two way |
An API is a published set of rules that lets one system read and write data in another. HubSpot documents its API in the HubSpot developer docs. HubSpot also releases dated API versions, and older versions stop working at their end-of-life date. That is one reason why we put middleware in the middle.
How is a custom HubSpot API integration built?
Scope
Discovery first. First, we learn which systems are involved, how they should connect and roughly how much data flows. Then you get a fixed price.
Map
We map each field: where it lives, which system owns it and what should happen when it changes.
Build and test
Next, we build the middleware and test it against your scenarios. Your team then runs user acceptance testing before go live.
Host and support
We monitor the integration after launch, fix breakages and keep up with API changes.
What we need from you
Access to the software, API documentation or credentials, a test account where possible, and information within 5 working days of asking.
Has Big Presence built custom HubSpot integrations before?
- A UK renewable energy and retrofit delivery partner: HubSpot connected to core systems by API.
- A UK Bikeability training provider: two-way integration through a custom middleware layer.
- A UK specialist art school: a booking platform connected to HubSpot through middleware.
- A UK training business: event booking data merged into HubSpot deals.
- A UK client: HubSpot to Airtable through webhooks, and PandaDoc to HubSpot through Zapier.
- Big Presence: we run this ourselves, with Instantly to HubSpot through n8n and Stripe payments into HubSpot, synced to Xero.
Why choose Big Presence as your HubSpot integration agency?
We are a revenue operations partner, not just a HubSpot implementer.
HubSpot Platinum
We are a HubSpot Platinum Solutions Partner based in Wilmslow, Cheshire. We deliver implementations, CRM integrations and custom development.
HubSpot middleware that lasts
Our integrations run through a middleware layer. So if a platform changes its API, we update the middleware instead of rebuilding.
Fixed price, clear scope
Projects are fixed price once scoped. New scope gets a new estimate.
Who hosts and supports a custom HubSpot API integration?
We host it
We host and look after the middleware. That covers monitoring, fixing breakages, handling API changes and key rotation.
You host it
Your own infrastructure? We hand over the working code and repository.
Ongoing support comes through a monthly support package: Big, Bigger or Biggest. We also recommend one at scoping.
Custom HubSpot API integration FAQs
How much does a custom HubSpot API integration cost?
A custom HubSpot API integration typically costs between £3,000 and £8,000 plus VAT when it connects one system to HubSpot, and between £10,000 and £30,000 plus VAT for multi-system builds or complex two-way logic. Most go live in 3 to 8 weeks. We confirm a fixed price once the project is scoped, and new scope gets a new estimate.
How long does it take?
The time a custom HubSpot API integration takes depends on the systems and the number of data flows. You get a timeline once scoping is done. The stages are always the same: scope, map the data, build and test, your testing, go live, then ongoing support.
Can you connect any software to HubSpot?
Software that has an API or can send webhooks is something we can look at for a custom HubSpot integration. We check its documentation at scoping and tell you plainly what is possible before you commit.
What is HubSpot middleware?
HubSpot middleware is a layer of code that sits between HubSpot and your other software. It moves and checks the data. If either platform changes its API, we update the middleware instead of rebuilding the integration.
Do you write code or use tools like Zapier and n8n?
Big Presence picks the method that suits the job, from custom code to tools like Zapier and n8n. Our live builds include custom middleware, webhooks, Zapier and n8n.
Who looks after it once it is live?
A custom HubSpot API integration can be hosted and looked after by Big Presence, or hosted by you with the code and repository handed over. Either way, ongoing support runs through a monthly support package.
Is this the same as your automation work?
A custom HubSpot API integration is not the same as our automation work. This page is about connecting HubSpot to other software through its API. Our automation and integration service covers HubSpot workflows, sequences and automation more broadly.
Where do we start?
A custom HubSpot API integration project starts with a scoping call. If you are not sure where the gaps are, we use a Growth Gap Analysis to find where your business is losing growth before we build.
What do you need connected to HubSpot?
Book a scoping call. Bring the name of your software, and then we will look at what a custom integration with HubSpot would involve.