Automated data capture is a general technique with a narrow economic sweet spot. It repays where documents arrive frequently, carry the same handful of fields each time, and where the sender has an incentive to be legible. Invoices sit exactly in that spot, which is why they are the classic application. Applying the same technique to documents that lack any of those three is where projects disappoint.
The three conditions
Volume, so setup effort amortises. Structure, so there are defined fields rather than prose. And a legible sender, because a supplier billing you wants to be paid and therefore prints clearly. Contracts fail the second condition, correspondence fails all three, and a document that arrives twice a year fails the first however structured it is.
Validation is what makes capture safe
Extracted values should be checked against things you already know: does the supplier exist, do the lines sum to the total, has this invoice number been seen, is the date plausible. These checks are cheap and catch a meaningful share of extraction errors before they reach a ledger. Capture without validation is a faster route to a wrong number.
Design the exception path first
Whatever the accuracy, some documents will need a person. Decide who, on what screen, with what information visible, and how quickly. Teams that design the happy path first and the exception path last end up with an exception queue that is unstaffed and invisible, which is how a capture project quietly stops delivering.
Questions people ask about automated data capture
How much setup does capture need?
Modern extraction is largely layout-agnostic, so less than it used to. The real setup effort is usually in the validation rules and in connecting to the systems downstream.
Does it work on handwritten documents?
Poorly, and it is worth designing around rather than hoping. Handwritten delivery notes are common and better handled by photographing at the point of signature than by extraction.
What is a realistic first target?
Header fields on emailed PDF invoices from your largest suppliers. That covers a large share of document count with the lowest difficulty.