OCR note working on delivery note numbers

[Clive Churchward 0]

I run a small courier company and I am trying to go paperless. The first problem I have hit is that after scanning in my delivery notes which are all pre-numbered. Evernote sometimes find the note number but sometime sometimes it does not. I think the problem is the gap between the six number. So if I scan in a note with the number 123456 if may find it. but the next note I scan 123457. It OCRs this six separate numbers. So I can't find it. I'm scanning B & W. Any suggestions ?  Regards Clive