This is the least glamorous advice on the site, and it will save you more time than almost anything else.
The failure it prevents isn't losing a document. It's having the document and not being able to produce it in the ninety seconds you have while someone is waiting.
The format
2026-03-14_school-email_address-change.pdf
Three parts, separated by underscores:
- The date, year first
- Who or where it came from
- What it is, in a few plain words
Date first, always
Four-digit year, two-digit month, two-digit day: 2026-03-14, never 14-3-26 or March 14.
Do this and your folder sorts itself into chronological order, permanently, with no effort. Every file you add drops into exactly the right place. Write dates any other way and your computer sorts them alphabetically, which puts January next to June and scatters a single month across the folder.
Use the date of the thing, not the date you saved it. An email sent on 14 March and saved on 2 April is 2026-03-14.
Then who and what
Short and plain, with no spaces. Hyphens between words, underscores between the parts:
2026-03-14_school-email_address-change.pdf2026-04-02_whatsapp-export_jan-mar.txt2026-04-19_receipt_swimming-pool.jpg2026-05-06_gp-letter_appointment-summary.pdf
You're naming it for the version of you who has to find it in eighteen months, under pressure, possibly with someone watching.
Why it matters more than it sounds
A folder of 400 files named IMG_2291, scan (3) and Document final FINAL is not an evidence library. It's a pile.
The same 400 files named this way are searchable at a glance. Need everything from the school? Search "school". Need everything from last spring? It's all together, in order. Asked for "the email about the address change"? You find it in seconds.
Keep a simple index alongside
For anything important, log two extra things in a list or spreadsheet next to the folder:
- Where it came from and how you obtained it. Sent to you directly, downloaded from a portal, requested from the school, exported from your phone. If anyone ever asks how you got something, the answer is already written down.
- What period it covers. Especially for exports and bundles. If your message export covers March to December, say so, because an unstated gap gets read, wrongly, as "nothing happened."
A few folders, not dozens
Keep the structure shallow. A handful of top-level folders by type, for example Messages, School, Medical, Receipts and activities, Third-party records and Correspondence, with date-first names inside each. Deep nests of subfolders hide things. The filenames do the sorting for you.
Do it at the moment you save it
The whole system depends on naming files as they arrive, not later. Renaming 400 files after the fact is miserable and error-prone, and you'll be doing it at exactly the moment you have least time.
Five seconds per file, at the moment you save it. Or an entire weekend, later, badly.
General information, not legal advice. Court process differs between countries and regions; check anything that matters to your case with a qualified lawyer where you live.
Chapter 7 of the workbook builds the full evidence library around this naming system. Worksheet B, the evidence tracker, is the index that sits alongside the folder: one row per item, with source, location, coverage and a strength rating.
See the workbook & spreadsheet