Nmbrs API: connect Nmbrs to your HR system, planning and accounts

What you can do with the Nmbrs API

• Create new employees from your HR system or onboarding in Nmbrs
• Pass leave and absence on to planning or HR
• Deliver hours worked and expense claims for the payroll run
• Pass wage components and salary changes on from one source
• Journal entries from the payroll run to your accounts

How the integration works

The integration uses OAuth 2.0 with a client you create in the Nmbrs developer portal; an Nmbrs user gives consent once. Every call goes to the REST API with an access token and a subscription key. Nmbrs counts calls per minute and per month, so the integration works in batches. For personal data strict agreements apply: only the fields the integration needs, with logging per action.

Facts about the Nmbrs API

Checked on 2 November 2026 against the official documentation. Limits, prices and versions change; the source is listed per row.

Fact	What the documentation says	Source
Authentication	OAuth 2.0 authorization code flow, the only form of access for the REST API. Every call carries a Bearer token and a subscription key (X-Subscription-Key) from the developer portal.	Nmbrs: Authentication
Token lifetime	Access token 1 hour. Refresh token 30 days and single-use; every renewal returns a new refresh token (offline_access scope).	Nmbrs: Authentication
Rate limits	Per product: Starter and Private 500 calls per minute (50,000 and 200,000 per month respectively), Verified Partners 1,000 per minute (500,000 per month). When exceeded, 429.	Nmbrs: Developer portal
Webhooks	Nmbrs mentions webhooks on the partner page; the details sit behind a login and not in the REST documentation.	Nmbrs: Building an integration
Test environment	No separate sandbox URL; there is a demo environment for developers that does not expire.	Nmbrs: Current state of the REST API
Version and deprecations	The REST API has no version in the URL; changes come through new fields and a changelog. The SOAP API is no longer supported from 1 March 2027.	Nmbrs: API for developers
Objects	Employees, employments, contracts, salary, wage components, hours, leave and absence, departments, cost centres, payroll runs, documents and more.	Nmbrs: Public REST API
API cost	Products in the developer portal without a price: Starter (immediate), Private (on request), Verified Partners (after a demo).	Nmbrs: Developer portal
n8n	No built-in node and no community node found; the integration runs through an HTTP step in n8n.	n8n documentation

What you need on your side

• An Nmbrs user with permissions on the companies the integration works in, who gives consent once
• A client in the Nmbrs developer portal (Starter is immediate, Private on request)
• A data processing agreement and a list of exactly the fields the integration may read or write
• A demo environment to build against before your real payroll data is touched

Where it often goes wrong, and how I prevent it

• Personal data: payroll and absence data are sensitive. The integration reads only the fields it needs and logs every action; the data processing agreement covers the rest.
• Access per company: a user only sees the companies they have permissions for. Where those are missing, Nmbrs returns a 403. I record that up front.
• Monthly cap: next to a limit per minute Nmbrs has a cap per month. The integration counts along and notifies you when the cap comes into view.
• End of SOAP: the SOAP API stops on 1 March 2027. An existing SOAP integration has to move to REST before that date.

In practice

An Nmbrs integration is not yet listed as In production with me. The approach is the same as for AFAS: one source per data item, a fixed key per employee, and a plain-language notification when something does not arrive. For payroll and absence data I build in a human check by default before anything is written.

What it costs

I build an Nmbrs integration as one scoped process for a fixed price, from €750. Maintenance and monitoring are a monthly fee: n8n management from €250 per month, server management €145 per server. In the free assessment we work out your process. All prices and what is included →

What I do not do

• I do not build new integrations on the SOAP API that Nmbrs stops on 1 March 2027.
• I do not let an integration write payroll or absence data without a human check, unless we explicitly agree otherwise.
• I do not do payroll administration; the integration passes data on, your payroll administrator remains responsible.

Frequently asked questions about the Nmbrs API

Does n8n have an Nmbrs node?

No, and no community node was found either. I connect Nmbrs through the REST API with an HTTP step in n8n.

What does the end of the SOAP API mean?

Nmbrs stops the SOAP API on 1 March 2027; after that only the REST API remains. If you have a SOAP integration now, it has to be rebuilt before that date. I only build new integrations on REST.

How many calls does Nmbrs allow?

That depends on the product in the developer portal: Starter and Private 500 per minute, with a cap of 50,000 or 200,000 per month; Verified Partners 1,000 per minute. Above that Nmbrs returns a 429.

Can I test without real payroll data?

Nmbrs offers no separate sandbox URL, but it does offer a demo environment for developers that does not expire. I build against that before the integration touches your real environment.

May an integration simply read salary data?

Only within the permissions of the user who gave consent and within the agreements in the data processing agreement. The integration gets no more fields than the task requires, and every action is logged.