Software · Consultancy · Payroll expertise
Payroll software that adds up.
To the cent. Software development for payroll, HR and accountancy
LK Software builds integrations, checks and tools for payroll providers, HR teams and accounting firms. Built by a team that knows payroll from the inside.
Since 2021
100+ companies use our software
5 packages integrated
Services
Six ways we can help
A one-off assignment, ongoing maintenance or one day a week of thinking along: you choose the form that fits your practice.
Software development
Custom API integrations, web applications and automation tools. Built by LK Software and a permanent network of mid-level and senior developers, scalable per project.
€ 75 per hour per developer excl. VAT
More about software developmentConsultancy
Advice on software selection, architecture, integrations and automation. Independent, concrete and technically grounded.
€ 110 per hour excl. VAT
More about consultancyPayroll & HR expertise
Payroll and HR specialists with more than ten years of experience, available for your project: for the rules, the checks and the acceptance.
€ 125 per hour excl. VAT
More about payroll & HR expertiseTraining
One day working with your developers on an integration with Nmbrs, Loket, Silverfin, Visionplanner or FiscaalGemak: by the end of the day you have everything you need to finish your project, instead of a week of research.
€ 950 per training day excl. VAT
More about trainingGeneral development projects
Websites, web, mobile and desktop applications outside the payroll domain. Delivered by LK Software with one or more mid-level developers from our network.
€ 75 per hour per developer excl. VAT
More about general development projectsMaintenance & support
Maintenance, monitoring and further development of existing tools and services. So that what works keeps working, also after delivery.
€ 75 per hour excl. VAT
More about maintenance & supportWhat we do
Software development for payroll, HR and accountancy
LK Software develops custom software for the payroll, HR and accountancy sector: from API integrations between payroll packages to checking tools, calculation modules and web applications that take over the monthly manual work.
For payroll providers and payroll bureaus: automated checks on the payroll administration, pension filings, daily wage calculations and integrations with Nmbrs and Loket.nl.
For HR departments: HR software and integrations that let employee data, leave and changes flow automatically between your HR system and the payroll administration.
For accounting and bookkeeping firms: integrations with Silverfin, Visionplanner and FiscaalGemak, so that figures and tax returns reach the file and the Dutch Tax Administration without retyping.
For software vendors: extra development capacity from a developer who already knows payroll and accountancy, plus training for your own team.
Integrations
Connected to the packages you work in
We have built integrations with the leading payroll, accountancy and reporting packages in the Netherlands. Is yours not listed? Then we build it.
Nmbrs
PayrollOpen source Python SDK for the SOAP API, plus dozens of custom integrations: exports, checks and mutations.
Loket.nl
Payroll & HRRead, convert and migrate documents and employee data, for example from Loket to Nmbrs.
Silverfin
AccountancyRetrieve figures and tax returns from the file and submit them automatically to the Dutch Tax Administration.
Visionplanner
ReportingRetrieve tax returns, signing dates and more automatically, present them and submit them to the Dutch Tax Administration.
FiscaalGemak
TaxNew tax returns via webhooks straight into the accountant portal, statuses kept in sync.
Microsoft SSO
IdentitySign in with the Microsoft account users already have, via Entra ID. One identity, fewer passwords and central access management.
Why LK Software
One point of contact who understands both the payslip and the code
Most developers have never heard of a daily wage, and most payroll administrators do not write software. LK Software sits exactly at that intersection: since 2021 we have built exclusively for the HR, payroll and accountancy domain, where a rounding error ends up directly in someone's pay.
Domain knowledge built in: UWV methodology, pension filings and collective agreement rules translated into tested, repeatable calculations.
From idea to production: requirements, architecture, development, testing, deployment and maintenance from one point of contact, with a team that grows with the project.
Reliable in production: automated tests, CI/CD and monitoring are standard, not optional.
Transparent rates: € 75 per hour per developer and € 125 for a payroll expert, all rates excl. VAT, a clear estimate up front, no surprises.
Accurate
Tested against real administrations before anything goes live.
Fast
Calculations that used to take hours run in seconds.
Connected
REST, SOAP, files or email: every source can be integrated.
Projects
A selection of what we have built
Nmbrs SDK
Python packages for the Nmbrs SOAP and REST API, open source, with automated tests and releases via GitHub Actions.
View projectPayroll Check Tool
Automatic checks of payroll administrations on more than 100 control points, before the pay run.
View projectWAZO daily wage
The UWV methodology as a C# application: the daily wage for WAZO benefits in seconds, straight from the API.
View projectReferences
What clients say
Lars helped us realise integrations with Silverfin, Visionplanner and FiscaalGemak. He was at home in both the technology and the accountancy practice, and you can see that in the result.
Ibrahim Kalin · accountancy software vendor
Lars thinks along from the payroll practice, not just the technology. What we asked for was delivered quickly and neatly, and he is still available for questions today.
Wilko Kluijtmans · senior payroll and HR consultant
Accountancy software vendor
For an accountancy software vendor serving accounting and bookkeeping firms we built the integrations with Silverfin, Visionplanner and FiscaalGemak, and Microsoft Single Sign-On for their platform. Firms now sign in with their own Microsoft account and figures flow to their reporting and tax packages without manual work.
See the integrationsFrequently asked questions
About custom software for payroll, HR and accountancy
Question not listed? Ask it via the contact form, you will get an answer within one working day.
What does custom software for payroll or HR cost?
Software development costs € 75 per hour per developer, consultancy € 110 per hour and a payroll or HR expert € 125 per hour. All rates are exclusive of VAT. You always get an estimate of the number of hours up front, so you know where you stand.
Can you build an integration with Nmbrs, Loket, Silverfin, Visionplanner or FiscaalGemak?
Yes. We already have integrations with these packages running in production. Integrations with other packages, such as AFAS, Exact or Twinfield, are built on request, as long as an API, export or file exchange is available.
Who does LK Software develop software for?
For payroll providers, HR departments, accounting and bookkeeping firms and software vendors in the payroll, HR and accountancy sector. Our software is now used by more than 100 companies.
How quickly can a project start and how long does it take?
You get a response within one working day with an estimate of approach, lead time and costs. A single integration or checking tool is often live within a few weeks; larger projects scale up with developers from our network.
What happens after delivery?
You get the code, the documentation and the explanation. If you want us to do the maintenance, we keep integrations up to date with API changes and respond to incidents within one working day, at € 75 per hour (excl. VAT) or a fixed monthly fee.
An integration, check or tool that does not exist yet?
Describe in a few sentences what you want to achieve. Within one working day you get an honest estimate of approach, lead time and costs.