No accounts department, no big system. The invoices and receipts arrive as PDF and e-invoice XML, and once a quarter somebody - you, or your accountant - wants them as a spreadsheet and wants the originals to still be there.
A folder called invoices-2026. In it: PDF invoices from suppliers, the odd e-invoice XML from a bigger client, and a handful of receipts. Nothing about the file names tells you the vendor, the number, the date or the amount - and retyping them into a spreadsheet is exactly the job you keep putting off.
Add the files, or the whole folder - sub-folders included. Nothing is uploaded anywhere.
The table shows vendor, invoice number, dates, currency, subtotal, tax, total due and the line items - and for every value, the word or line it was read from.
When one supplier's layout reads wrongly, correct the cell and save it as a rule for that supplier. Next month's invoice from them is read that way.
Excel or CSV with the columns you choose, or the line items on their own - ready for your books or for your accountant. The originals stay in a local archive.

Vendor, customer, invoice number, issue date, due date, currency, subtotal, tax, total due and the line items - the columns an accountant asks for, without retyping them.
Factur-X, ZUGFeRD, UBL, CII, CFDI, NF-e, FatturaPA and Facturae are read from the XML itself - and so is the XML embedded inside a PDF. No picture, no guessing.
No upload, no cloud account, no network. Useful when the invoices are not only yours - a client's paperwork never leaves your machine.

The row in the spreadsheet is not the document. Every invoice taken in is copied into a local archive before anything is read from it - including the ones that could not be read at all. Months later, Tools → Original documents... searches that archive by invoice number, by supplier, or by the file name it came in as, and the original opens as the PDF it always was.

It does not read scans or photos. If a PDF has no text layer - a photographed receipt, a faxed statement - BillSight says so and reads nothing from it, rather than inventing numbers. Those still have to be typed in by hand, and it will tell you which ones they are instead of quietly skipping them.
Everything happens on this computer - your invoices are never uploaded.