Every business accumulates files, and most accumulate them without any convention at all. The folder contains quote.pdf, quote2.pdf, quote-final.pdf, quote-final-v2.pdf, scan0043.pdf, IMG_2281.jpg, and Document1.docx. Everyone recognises this and most people regard it as an unavoidable consequence of being busy. It is not, quite: it is the consequence of naming files at the moment of saving, when the only reader in mind is yourself, five seconds from now, who knows exactly what this is. The reader who matters is somebody else, or you in eighteen months, and neither of them has that context.
The usual answer - search - is weaker than people assume, because search can only find what you can describe. Searching for an invoice works if the word invoice is in the name or the text; it does not work if the file is called scan0043 and the contents are an image of a document rather than text. Modern systems can often read text inside images, which helps, but that only finds documents whose words you remember. It will not tell you which of the four quotes was the one that was accepted, and that is usually the actual question.
What works is dull and takes a few seconds: put the date first in a form that sorts correctly, then the customer or project, then what the thing is. A file called 2026-09-18-mano-bustas-quote tells you everything at a glance, sorts itself into chronological order without any effort, and can be found by searching for the customer, the year or the type. The date-first convention is the part people skip and the part that does most of the work, because it makes a folder self-organising: the newest thing is always at one end, and a year's work falls into order with no filing at all.
Two refinements are worth the trouble. Use a consistent word for each kind of document - always quote, never sometimes estimate and sometimes proposal - because search matches the word you actually used, not the one you meant. And when a document is superseded, say so in the name of the old one rather than relying on v2, v3, final, final-final, which is a system that has never once worked and which leaves nobody able to identify the current version. None of this needs software or a policy. It needs the habit of spending three seconds writing a name for a stranger, which is the only part that requires any discipline at all.