Webinar on Thursday 26 November at 11:30 (in Dutch)
Together with Aelio, we will show you in 45 minutes how WZH connected external staffing and invoice checks. Sign up
Woonzorgcentra Haaglanden (WZH) connected the staffing platform Aelio to Elari. Since then, staffing invoices are rejected more than four times less often, without WZH having to replace a single existing system.
Control over staffing, and now over invoices too
Through the MSP services of Aems on the Aelio platform, WZH brought requests, contracts, rates and hours together in one place. The question soon arose of how to bring that same control to the financial process. Because invoice processing was still largely manual:
- Planners only checked the hours, because they did not know the rate agreements.
- Invoices went through several approvers, and progress had to be chased by phone every week.
- Changes came in after the fact, leading to many credit notes.
- The full cost picture was only available when it was too late to adjust.
From hours worked to purchase order
When the MSP services went live in January 2025, WZH connected Aelio to Elari Purchase to Pay. Since then, every staffing invoice follows the same three steps:
1. Hours and rates recorded
Hours worked are reconciled and approved every week. The rates are stored in Aelio. This prevents credit notes afterwards.
2. Purchase order in Elari
Elari automatically turns the approved hours and rates into a purchase order.
3. Invoice matched
Elari matches the invoice to the order in Invoice Processing. If everything is correct, it is ready for payment.
For Maarten Brandwijk, Director of Operations at WZH, the biggest difference is for the people who used to check every invoice by hand:
"By recording the contractual rate agreements in the Aelio platform, we can now match all invoices without involving planners and team leaders."
Maarten Brandwijk, Director of Operations at WZH
What the integration changes
The integration does more than take over invoice checks. It also changes how WZH works with external staff:
- One data flow: record hours and rates once, and they flow through automatically.
- Checks before payment: you see discrepancies before approval, not afterwards.
- Insight while the month is running: costs per supplier and location, while you can still adjust.
- Easy to expand: a new staffing supplier can be connected within a day.
- Existing systems stay in place: no migration, and both Aelio and Elari are ISO 27001 certified.
Elari measures where time is lost
Elari helps organisations in healthcare, education and the non-profit sector spend as little time as possible on getting what they need. That is our North Star. Because Elari continuously measures how long processes take, it stood out that invoices for external staff consistently took longer. Jasper van Ommen, Manager Customer Success and Data at Elari, saw that change with the integration:
"No more manual digging, just pure time savings."
Jasper van Ommen, Manager Customer Success and Data at Elari
More than four times fewer rejected invoices
Invoices that come in through the integration are rejected more than four times less often than other invoices. WZH notices this across the organisation:
- Operational: the monthly manual invoice check has largely disappeared.
- Financial: staffing costs are visible while the month is running.
- Compliance: every euro paid can be traced back to a shift, a professional and a rate.
- Suppliers: they no longer have to chase approvals and credit notes.
The administration team notices a big difference too, says Maarten:
"Every invoice for external staff is ready for payment in Elari on the day it is processed."
Maarten Brandwijk, Director of Operations at WZH
At WZH, staffing and invoicing now fit together seamlessly, from shift worked to invoice paid. Curious whether this could work for your organisation too? In the webinar, we will show you how.
