What is UBL? Definition and explanation
UBL stands for Universal Business Language – an international standard for exchanging electronic business documents, such as invoices, credit notes, and orders.
In simple words: UBL is a standardized language in which invoice data is stored in an XML file. Just as PDF is a standard for documents that look the same everywhere, UBL is a standard for invoice data that can be processed automatically by computers.
Why is UBL important?
A normal PDF invoice is a 'picture' that people can read, but computers cannot process automatically. A UBL invoice contains structured data that can be read directly into accounting software without manual work.
Example:
• Traditional: You receive a PDF invoice, read the data, and enter it manually into your accounting system.
• With UBL: You receive a UBL XML file, your software automatically reads the invoice number, amount, VAT, and other fields and books the invoice automatically.
This saves a huge amount of time, prevents typos, and speeds up the payment process.
Difference between UBL, PDF, and other formats
There are several ways to send an invoice. Here are the main differences:
1. Paper invoice
• Printed on paper and sent by mail
• Disadvantage: Slow, expensive, manual processing required
• Nowadays rare in business transactions
2. PDF invoice (by email)
• Digital document that looks like a paper invoice
• Advantage: Fast, cheap, everyone can open it
• Disadvantage: Data must be manually retyped into accounting system
• Most common in the Netherlands for B2C and small businesses
3. UBL invoice (XML file)
• Structured data in XML format according to UBL standard
• Advantage: Fully automatic processing, no human intervention
• Disadvantage: Not readable for humans (you need software)
• Often combined: UBL XML + PDF for both automatic processing and human-readable version
4. EDI (Electronic Data Interchange)
• Older standard for electronic message exchange
• Mainly used in specific sectors (retail, logistics)
• More complex and expensive to implement than UBL
5. ZUGFeRD / Factur-X
• Hybrid format: PDF with embedded XML data
• Mainly used in Germany/France
• Combines UBL advantages with PDF readability in one file
Trend: UBL is becoming increasingly popular because it is an open standard (free, not owned by one company) and is supported worldwide.
NLCIUS: The Dutch UBL standard
In the Netherlands, we don't just use the international UBL standard, but a Dutch adaptation called NLCIUS (Netherlands Court of Audit Implementation User Specification).
What is NLCIUS?
NLCIUS is a Dutch profile of the European invoicing standard EN 16931. It contains additional rules and fields that are specific to the Dutch situation.
Difference between UBL and NLCIUS:
• UBL: International standard with hundreds of possible fields
• NLCIUS: Dutch subset of UBL with required and recommended fields for the Netherlands
Why NLCIUS?
The Netherlands has specific requirements that are not in the general UBL standard:
• VAT rules: Dutch VAT categories and rates (21%, 9%, 0%)
• OSS regulation: Fields for One-Stop-Shop for EU sales
• CoC number: Mandatory field for Chamber of Commerce number
• IBAN format: Dutch bank account specifications
• Language: Standard Dutch, with support for multilingualism
NLCIUS versions:
• NLCIUS 1.0: First version (2017)
• NLCIUS 2.0: Current version since 2020, based on EN 16931
• Updates follow European developments
Important: If you invoice the Dutch government (State, municipalities, provinces, water boards), NLCIUS is mandatory.
When is a UBL invoice mandatory?
Whether you must send UBL invoices depends on your customers and sector:
1. Mandatory: Invoicing to Dutch government
Since April 2017, UBL (NLCIUS) is legally mandatory for all invoices to:
• Central government (ministries, implementing organizations)
• Provinces
• Municipalities
• Water boards
• Independent administrative bodies (ZBOs) such as UWV, SVB
Threshold: From €5,000 annual revenue with a government agency, you are required to send UBL invoices. Below this threshold you may still use PDF, but many agencies only accept UBL.
2. Mandatory: Peppol network suppliers
If you supply to companies connected to the Peppol network (Pan-European Public Procurement OnLine), you often have to send UBL invoices via this network.
3. Often required: Large business customers
More and more large companies (especially multinationals and corporates) demand UBL invoices from their suppliers to automate their purchasing process:
• Retail chains (Albert Heijn, Jumbo, etc.)
• Technology companies
• Logistics service providers
• Construction and installation sector
4. Optional but beneficial: B2B sales
For 'regular' business customers (SMEs), UBL is not mandatory, but more and more companies prefer it to automate their administration.
Future: The EU is working on legislation that makes electronic invoicing (like UBL) mandatory for all B2B transactions, possibly from 2028.
Benefits of UBL invoices
Why would you use UBL invoices, even if it's not mandatory?
For the sender (you as supplier):
• Faster payment: Automated processing means invoices are approved and paid faster
• Fewer errors: No manual entry = fewer typos and disputed invoices
• Lower costs: Save on paper, printing, postage, and administrative hours
• Professional appearance: Show that you are technologically up-to-date
• Compliance: Automatically meet government rules and customer requirements
For the receiver (your customer):
• Automatic processing: Invoice is read directly into accounting system
• No manual entry: Save administrative hours
• Fewer errors: No typos when retyping data
• Faster approval: Workflow automation speeds up internal approval process
• Better control: Structured data makes reporting and control easier
Environment:
• Paper saving: No printing and posting needed
• CO2 reduction: Less transport of paper invoices
Figures: Companies that switch to UBL/e-invoicing save on average 60-80% on invoicing costs and speed up payment terms by 20-30%.
How do you create a UBL invoice?
You do not create a UBL invoice manually – you need software that generates the correct XML structure.
Option 1: Use accounting software with UBL export
Most modern accounting software supports UBL:
• Xero/QuickBooks: UBL export and import built-in
• Exact Online: Full UBL support
• Visma: UBL module available
• Yuki: Automatic UBL generation
• Twinfield: UBL functionality standard
Option 2: Use specialized invoicing software
Software like Winkel Factuur automatically generates UBL invoices alongside PDF versions:
• You create an invoice as you are used to
• Software automatically generates both PDF and UBL XML
• UBL automatically complies with NLCIUS standard
• Validation checks if all required fields are present
Option 3: Peppol Access Point services
For sending via the Peppol network you need an Access Point:
• Simplerinvoicing (Pagero): Popular Dutch provider
• Tradeshift: International player
• Basware: Enterprise solution
• You send invoices via their platform, they ensure correct UBL format and transmission
What is in a UBL invoice?
A UBL XML file contains structured fields such as:
• Identification: Invoice number, invoice date, due date
• Supplier: Name, address, CoC number, VAT number, IBAN
• Customer: Name, address, VAT number, reference
• Invoice lines: Per line: description, quantity, unit price, VAT rate
• Totals: Subtotal, VAT amounts per rate, total amount
• Payment information: IBAN, payment term
The software ensures that all this is correctly formatted according to the UBL/NLCIUS standard.
Peppol: The European invoice network
Peppol (Pan-European Public Procurement OnLine) is a European network for exchanging electronic invoices and other business documents.
How does Peppol work?
Peppol is like an 'email system for invoices':
1. You send an invoice via your Peppol Access Point (a certified service provider)
2. The network ensures secure transmission
3. The invoice arrives at your customer's Access Point
4. Their system processes the invoice automatically
Peppol Advantages:
• Standardized: Works the same in all 35+ Peppol countries
• Secure: Encrypted transmission with certification
• Reliable: Receipt confirmation and tracking
• Mandatory for government: All Dutch government organizations are connected
Peppol ID:
Every company on the Peppol network has a unique ID, often based on CoC number:9999:NL[CoC-number]
Example: 9999:NL12345678
Costs:
Using Peppol costs money – you pay your Access Point provider a monthly subscription (usually €10-50/month depending on invoice volume).
When do you need Peppol?
• When invoicing government (usually mandatory via Digipoort or Peppol)
• If your customer asks for it
• For international B2B within Europe (increasingly common)
Alternative: Digipoort
In the Netherlands you can also send invoices to the government via Digipoort. This is the older system, but Peppol is becoming the new standard.
Validating and testing UBL
A UBL invoice must be valid – that is, comply with all rules of the NLCIUS standard. Otherwise your invoice will be rejected.
What is validated?
• Mandatory fields: Are all required fields present (invoice number, date, VAT number, etc.)?
• Correct format: Are dates, amounts, and VAT numbers correctly formatted?
• Consistency: Do the totals match the sum of the invoice lines?
• Schematron rules: Does it meet all NLCIUS business rules?
Free validation tools:
• STPE (Simplerinvoicing Test Platform): Online validator especially for NLCIUS
→ Go to stpe.nl and upload your UBL XML file
→ System gives detailed feedback on errors
• OpenPeppol Validator: European validator for general UBL
→ peppol.helger.com/public/menuitem-validation-bis3
• Logius Validator: Dutch government validator
→ validatie.simplerinvoicing.org
Common errors:
• Missing VAT number: NLCIUS requires supplier VAT number
• Wrong date format: Must be YYYY-MM-DD (e.g. 2025-01-15)
• Amounts without 2 decimals: Must be e.g. 100.00, not 100
• Wrong VAT category code: Use S (standard), Z (zero), or E (exempt)
• Totals do not match: Sum of lines must exactly match total
Tip: Use software (like Winkel Factuur) that automatically validates before the invoice is sent. Then you prevent invoices from being rejected.
Implementing UBL in your company: Step-by-step plan
Do you want to switch to UBL invoicing? Follow these steps:
Step 1: Inventory your situation
• Do you invoice the government? Then UBL is mandatory
• Do business customers ask for UBL?
• How many invoices do you send per month?
• Which accounting software do you use now?
Step 2: Choose a solution
• Small volumes (<50 invoices/month): Use invoicing software with UBL export like Winkel Factuur
• Medium volumes (50-500): Connect your accounting software with UBL module
• Large volumes (>500): Consider Peppol Access Point + automatic connection with ERP
Step 3: Test your UBL invoices
• Create a test invoice
• Validate via STPE.nl or other validator
• Resolve any errors
• Ask customer to accept test transmission
Step 4: Inform your customers
• Let business customers know that you offer UBL
• Ask if they have a preference (Peppol ID, email with UBL attachment, etc.)
• Explain that this yields faster processing and payment
Step 5: Go live
• Start invoicing via UBL
• Optionally send PDF as well for their administration
• Monitor if invoices are received correctly
• Adjust process where necessary
Cost indication:
• Small businesses: €0-20/month (many invoicing software has UBL export standard)
• Peppol connection: €20-50/month for Access Point
• Enterprise ERP connections: One-time €1,000-10,000+ for customization
ROI: You often earn back the investment within 3-6 months through time savings and faster payments.
Frequently asked questions about UBL
Do I have to stop PDF invoices if I use UBL?
No! Most companies send both UBL and PDF. The UBL is for automatic processing, the PDF for human-readable archiving. Many software creates both automatically.
Can I read UBL invoices myself?
UBL XML files are technically readable in a text editor, but not very user-friendly. You need a UBL viewer or accounting software to display them neatly.
Is UBL secure? Can the invoice be modified en route?
When sent via Peppol, invoices are encrypted and manipulation is virtually impossible. With email you can digitally sign the UBL or send a hash for verification.
Does UBL also work internationally?
Yes! UBL is an international standard. However, each country can have its own 'profile' (like NLCIUS in the Netherlands, XRechnung in Germany). Peppol ensures compatibility between countries.
What if my customer doesn't have UBL software?
Then they can ask you to just keep using PDF. UBL only makes sense if the receiver can process it automatically.
Can I also send credit notes via UBL?
Yes, the UBL standard also supports credit notes, orders, packing slips, and other business documents.