Integrations
Connect Billnado to WinBooks Connect via Mailbox
Use Email to Connect to deliver invoices and credit notes from Billnado and check receipt in the WinBooks Connect dossier.
Updated on October 22, 2026
Mailbox delivers invoices and credit notes from Billnado to your accountant’s WinBooks Connect dossier. You need access to the Billnado administration and an active Email to Connect receiving address. Your accountant configures further processing in WinBooks.
Step 1: have Email to Connect checked for the dossier
Ask your accountant for your WinBooks Connect dossier’s existing collection address. If there is no address yet, someone with the accounting profile can select the correct licence and dossier in the WinBooks portal. Add the module through + Modules > Email to Connect > Add module. Configure and save the dossier address in Configuration.
WinBooks supports domains including @winbooksconnect.be, @myinvoices.be and @mydocs.be. Use the address actually configured for your dossier. The WinBooks guide to creating a collection address describes the setup.
Ask your accountant whether all documents may arrive at the same address or whether separate purchase and sales destinations are provided.
Step 2: copy the addresses into Billnado
Open the correct administration in Billnado and go to Settings > Integrations > Accounting. Select Mailbox under Accounting software.
| Billnado fields, for both PDF and UBL | WinBooks Connect destination |
|---|---|
| Email for sales invoices | Use the confirmed Connect destination for sales invoices. |
| Email for sales credit notes | Use the sales credit note destination your accountant confirms for the same dossier. |
| Email for purchase invoices | Use the confirmed Connect destination for supplier invoices. |
| Email for purchase credit notes | Use the purchase credit note destination your accountant confirms for the same dossier. |
Complete the PDF and UBL destination for each document type. If one collection address receives all document types and both formats, it may be entered in all eight fields. This does not create separate journals in WinBooks.
WinBooks Connect supports display of PDF and XML/UBL, among other formats. Billnado sends one file per document: a suitable UBL takes priority, otherwise the available PDF is sent. Agree whether further accounting processing of that UBL is also configured in the dossier; displaying and final posting are separate steps.
Step 3: configure the conditions and save
Choose Deferral period for automatic export and match Maximum attachment size to the receiving dossier. Billnado defaults to 2 MB per file. Discuss whether Only send UBLs that are PEPPOL-compliant is appropriate for your sales documents.
Check the business, Connect dossier and addresses. Choose Save to save the settings.
Note: activation may allow documents to flow automatically to the accounting office. When switching, check which documents have already been delivered to Connect through another channel.
Step 4: check receipt in Connect
Together with your accountant, select a document not yet submitted. Open it using the eye icon in Billnado, check its number and amount and choose Export. This delivers the file to the configured address.
Ask your accountant to check My Desk or further processing in the correct Connect dossier for the document. Check the document type, readability and destination for further posting. An export record in Billnado does not confirm that the document has been posted in WinBooks.
Daily use and troubleshooting
Documents are delivered to Connect after the deferral period. Postings, corrections and payment statuses from WinBooks are not sent back to Billnado through Mailbox.
If a document is missing, have Email to Connect checked for activation and confirm that the address still belongs to the same dossier. Also check the file size and processing in Connect. Do not use an arbitrary address with a WinBooks domain: only the configured dossier address is the correct destination.
Select None under Accounting software and save to disable future automatic exports. Documents already delivered are not removed from Connect.