After processing thousands of bank statements, invoices, and receipts through Claude Vision API, I've learned that financial document OCR is harder than it looks. Here's what actually works in production.

The Problem: Why Traditional OCR Fails on Financial Documents

Traditional OCR tools like Tesseract or AWS Textract struggle with financial documents for three reasons:

Table structure is implicit — Banks don't use HTML tables. Columns are separated by whitespace, making it hard to know where one column ends and another begins.

Numbers must be perfect — Confusing 1 with l or 0 with O creates accounting errors. A single misread digit can break double-entry bookkeeping.