The UWV is one of the largest e-invoice recipients in the Netherlands and sets specific requirements for the content and structure of invoices. With eConnect, you can send invoices to the UWV via Peppol, but it is important to know the correct cash flow, the right OINO number and the mandatory fields. This article explains everything step by step.

The UWV distinguishes two cash flows, each with its own OINO number (Organisation Identification Number Government) and specific invoice requirements:

Important: the OINO is always 20 digits long, including leading zeros. If you leave out any zeros, the invoice will not be delivered.

Use the OINO of the correct cash flow when creating the invoice. If you are not sure which cash flow your invoice belongs to, check with your contact person at the UWV.

The Large Cash Flow has the most extensive requirements. Your invoice must meet the following conditions:

Mandatory fields at document level:

• Purchase order number: the UWV order number you received. Maximum one order number per invoice.
• Legal invoice data: Chamber of Commerce number, VAT number and IBAN of the supplier must be fully completed.
• Supplier contact details: your email address and phone number must appear on the invoice.

Mandatory fields per invoice line:

• Product code (BuyersItemIdentification): each invoice line must contain the product code the UWV included in the purchase order. This is the code the UWV uses to identify the delivered service or product.
• Reference to order line: each invoice line must refer to the corresponding order line.

Tip: you can find the product codes in the purchase order you received from the UWV. Copy them exactly, as deviating codes lead to rejection.

The Small Cash Flow has slightly different requirements:

Mandatory fields at document level:

• Purchase order number or cost centre: enter the order number from the UWV purchase order, or the cost centre if no order number is available.
• UWV contact person name: the name of your contact person at the UWV must appear on the invoice.

Mandatory fields per invoice line:

• Order line numbers: each invoice line must refer to the corresponding line in the UWV purchase order.

Check the total amount: the total amount of your invoice must not exceed the amount on the corresponding purchase order. A higher amount leads to automatic rejection.

The UWV uses different postal addresses per cash flow. Although this is not relevant for Peppol delivery (the invoice is delivered electronically), it is good practice to include the correct address on the invoice:

• Large Cash Flow: Postbus 56011, 1040 AA Amsterdam
• Small Cash Flow: Postbus 57025, 1040 CZ Amsterdam

When you receive a purchase order from the UWV via Peppol, you can convert it to an invoice in the eConnect platform with just a few clicks. This is called the Order flip. The platform automatically carries over the order data (order number, lines, product codes, amounts), so you only need to review and send.

The Order flip prevents typos and ensures your invoice meets all UWV requirements straight away, because the mandatory fields are automatically taken from the purchase order.

Need to correct an invoice? The UWV only accepts full crediting: credit the full original amount and then create a new invoice with the correct amount. The credit note must have a new, unique invoice number.

Before you can invoice the UWV for the first time, you need to register as a supplier. You do this via the eConnect platform by activating your organisation and sending an invoice to the correct OINO number. The UWV recognises you as a new supplier as soon as the first invoice arrives.

If you already have a contract with the UWV and have received a purchase order, you can invoice via Peppol right away. No separate registration step is needed at eConnect, as the Peppol registration is handled automatically when you activate your organisation.

If your invoice does not meet the requirements, you will receive an error message with a UWV-specific error code. The UWV applies its own validation rules on top of the standard Peppol/NLCIUS validation.

Important: the UWV validates the UBL-XML of the e-invoice, not the PDF representation. A value that is visible on the PDF but is in the wrong UBL field in the XML -- or missing there -- leads to rejection. For error codes always check the XML fields, not the PDF.

Tip: received an error code not listed here? Contact support@econnect.eu and we will help you further.

UWV017 is not a standard field validation but an invoiceCheck: the eConnect platform checks via the InvoiceCheck service in the UWV system (PeopleSoft) whether the order number provided is a valid, existing UWV order number in combination with the supplier's Chamber of Commerce number. If no valid combination is found, the order number field is cleared and UWV017 follows.

Error message per cash flow:

• GG: "No valid UWV order number could be found in combination with your Chamber of Commerce number." / customer phrases: "invalid order number UWV", "no valid order number in combination with your Chamber of Commerce number"
• KG: "No valid cost centre number or order number of UWV could be found in combination with your Chamber of Commerce number."

Purchase order delivery method plays no role. UWV017 (and UWV014) check the UBL content of the e-invoice against PeopleSoft/order fields -- not how the related UWV purchase order was sent (email, Peppol or otherwise). A PO via email does not by itself cause UWV017 or UWV014; the error remains data/content (order number, Chamber of Commerce match, product codes). Order flip remains possible only when the purchase order arrived via Peppol.

Requirements for the order number:

• Field: Invoice/OrderReference/ID (maximum one order number per invoice -- multiple order numbers result in UWV009).
• Format: AN10 (alphanumeric, maximum 10 characters), with at least 7 digits.
• The order number must actually exist at the UWV and be linked to the Chamber of Commerce number you are submitting with.

Solution:

1. Check the order number on the UWV purchase order and copy it exactly into Invoice/OrderReference/ID (format AN10, at least 7 digits).
2. Check that the Chamber of Commerce number on the invoice is the number to which the UWV order was assigned. A mismatch between order number and Chamber of Commerce number is the most common cause of UWV017.
3. The most reliable route is the Order flip: convert the purchase order sent by the UWV via Peppol into an invoice, so the order number and Chamber of Commerce link are automatically copied correctly.

Note (KG): when the order number field is cleared by the invoiceCheck, you will only see UWV017 and not UWV013 (order line number). The invoiceCheck is centrally configured and cannot be adjusted per supplier.

UWV014 means that on one or more invoice lines the product code is missing or does not meet the required format. The product code is mandatory in the Large Cash Flow (GG) and by default optional in the Small Cash Flow (KG).

Requirements for the product code:

• Field: Invoice/InvoiceLine[n]/Item/BuyersItemIdentification/ID.
• Format: A2_N4_N3 (2 letters, 4 digits, 3 digits), or N4 (4 digits), or N3 (3 digits).

Solution:

1. Include the product code from the UWV purchase order on each invoice line in Item/BuyersItemIdentification/ID, in format A2_N4_N3, N4 or N3.
2. If the product code cannot be placed in that field, eConnect (GG flow only) also recognises the code from other fields -- provided it has a prefix such as productcode, product or code (optionally with UWV, case-insensitive, a : after the prefix is allowed), for example in Item/Name, Item/Description or InvoiceLine/Note.
3. In the fields OrderReference/ID, AccountingCost and AccountingCostCode, a product code without prefix is recognised as soon as it matches the format -- for some suppliers the only way to include a product code.
4. The most reliable route is again the Order flip, where product codes from the purchase order are automatically placed on the invoice lines.

1. Log in to platform.econnect.eu and click Create invoice.
2. Search for the UWV as recipient using the OINO number of the correct cash flow.
3. Enter the purchase order number you received from the UWV.
4. Add the invoice lines with the correct product codes and order line numbers.
5. Check that your Chamber of Commerce number, VAT number, IBAN, email address and phone number are correctly filled in.
6. Check the total amount: it must not exceed the order amount (for the Small Cash Flow).
7. Click Send.

The invoice is delivered to the UWV via Peppol. You can track the status in your Outbox.

Want to know how e-orders from the UWV work? Read more about receiving e-orders via Peppol.