Connecting HubSpot to Exact Online
For keeping companies and contacts in sync, the free Exact Online app via HubSpot Data Sync is usually the starting point — it costs nothing and covers the basics. If you also want to create invoices from won deals and see the payment status back in HubSpot, an off-the-shelf connector such as KoppelHet costs €74.95 per month (KoppelHet, 2026); a custom build starts at an indicative €1,500.
- Fixed monthly fee
- Fixed project price up front
- Microsoft and Google
- Response to your request within one business day
What does an integration between HubSpot and Exact Online deliver?
An integration between HubSpot and Exact Online saves above all on double entry: customers that sales creates in HubSpot appear automatically as a contact in Exact, and a won deal no longer has to be turned into an invoice by hand. Just as valuable is the way back — sales can see in HubSpot whether an invoice is outstanding or paid, before the next sales conversation. You can see what such an automated flow looks like in the Flow Lab; what integrating costs in general is covered in What does an API integration cost?
The honest story: for some businesses the free Data Sync is simply enough. Paying for a connector or a custom build only makes sense once you want to automate the invoice flow and custom fields — which is why we set out all the routes side by side below.
Four routes, from free to custom.
| Option | Type | Indicative cost | Suitable for |
|---|---|---|---|
| HubSpot Data Sync (Exact Online app) | Standard app | Free within any HubSpot plan; custom field mappings from Operations Hub/Data Hub Starter, around $9–15 per user per month (HubSpot, 2026) | Keeping companies and contacts in sync, without an invoice flow |
| KoppelHet | Off-the-shelf connector | €74.95 per month, first 30 days free (KoppelHet, 2026) | Invoices from won deals plus payment status back in HubSpot |
| APIcenter | Integration platform | Monthly subscription; rate depends on the connected applications, on request (APIcenter, 2026) | Broader sync of orders, products and customers alongside the CRM |
| Make / Zapier / Power Automate | iPaaS workflow | Licences from $9 per month (Make, 2026) up to around $30 per month (Zapier, 2026) | Standalone triggers alongside a standard sync, such as a Slack alert on payment |
| Custom build on the API | Custom | Indicative €1,500–€15,000 one-off (see What does an API integration cost?) | Custom deal logic, multiple ledgers or non-standard fields and volumes |
What does sync — and what doesn't?
The core: contacts come across on every route, the invoice flow only on the paid routes. The free Data Sync keeps companies and contacts in sync in both directions, but creates no invoices and sends no payment status back. For that you need a connector such as KoppelHet or a custom build.
| Data | Off-the-shelf connector | Custom integration |
|---|---|---|
| Companies & contacts | Yes | Yes |
| Sales invoice from a won deal | Yes — with paid connectors; not in the free Data Sync | Yes |
| Payment status per deal back in HubSpot | Yes — with paid connectors such as KoppelHet | Yes |
| Custom fields | Limited — in Data Sync, custom field mappings require Operations Hub/Data Hub Starter | Yes |
| Custom deal logic (e.g. invoicing per stage or per line) | No | Yes |
| History from before the start date | No | Optional |
Three questions that settle the choice.
Do you only need to keep contacts in sync?
Yes → the free HubSpot Data Sync is enough; start there and pay nothing. No → you need a paid connector or a custom build for the invoice flow.
Does an off-the-shelf connector cover your fields, VAT logic and volumes?
Yes → a connector such as KoppelHet or APIcenter is the fastest and cheapest route. No → a custom build on the APIs stops you from constantly working around the limitations.
Do you want custom logic, such as invoicing per deal stage or multiple ledgers?
Yes → a custom build; off-the-shelf connectors follow one fixed template. No → stick with standard and keep management simple.
Rule of thumb: start free with Data Sync, only pay for a connector once you want to automate invoices, and only choose a custom build once the standard demonstrably pinches.
Four pitfalls with a HubSpot–Exact integration.
Two integrations syncing the same thing
Running the free Data Sync and switching on a connector as well gets you duplicate or conflicting records. Designate one integration as leading per data type and switch off the overlap in the other.
Skipping VAT and ledger mapping
An invoice that comes in on the wrong ledger account or VAT code costs your bookkeeper more time than creating it by hand ever did. Set up the mapping first and test with draft invoices before anything is posted for good.
Forgetting custom fields
In the free Data Sync, custom field mappings require an Operations Hub licence, and not every connector knows all your custom fields. Run through your field list up front, otherwise it's exactly the data you did it for that gets left behind.
Nobody checks whether it's still running
Exact Online enforces API limits per minute and per day; an integration that hits them often fails silently. Arrange monitoring with an alert on errors, so you hear about it before accounting does.
More combinations are in the integrations overview — for example Pipedrive ↔ Moneybird for those working with a lighter CRM and Moneybird, or Bullhorn ↔ AFAS for recruitment.
What people ask us up front.
What does an integration between HubSpot and Exact Online cost?
The free Exact Online app via HubSpot Data Sync costs nothing and keeps companies and contacts in sync. The off-the-shelf connector from KoppelHet costs €74.95 per month (2026) and adds invoicing and payment status. A custom integration on both APIs costs an indicative €1,500 to €15,000 one-off, depending on the number of flows and the requirements for error handling.
How long does it take to connect HubSpot to Exact Online?
The free Data Sync is switched on in a quarter of an hour. An off-the-shelf connector such as KoppelHet you typically set up within half a day, including field mapping and a test invoice. A custom integration usually takes two to six weeks of lead time, including testing and a controlled go-live.
What if the free Data Sync turns out not to be enough?
Then you don't have to start over. The Data Sync stays usable for contacts, and you add a paid connector or a custom build for the invoice flow. Do make sure that per data type one integration is leading, otherwise you get duplicate or conflicting records.
Who manages and monitors the integration?
With an off-the-shelf connector, the vendor handles the maintenance and support is included in the monthly fee; setting up and checking the mapping stays your job. With a custom build, monitoring and error alerts are part of the agreements you make with the developer — we set up alerts by default, so an integration never fails silently.
Do we need to switch CRM or accounting package?
No. HubSpot and Exact Online both have a mature API and several ready-made connectors; almost any combination of plans can be connected. A switch is only worth considering if one of the two systems no longer fits even apart from the integration.
Ready to make HubSpot and Exact work together?
Book an intro call — or start with the free Operations Scan and see where the hours leak away in your process.