Naming your files so you can find them in two years
A naming convention is judged on one thing only: does it hold when the folder has three hundred documents?
The date first, in international order
2026-03-14 sorts itself. 14-03-2026 sorts by day, which means nothing, and 14 March 2026 sorts alphabetically, which means nothing either.
That is the only rule that really matters: a folder whose files start with a year-month-day date is a sorted folder, even if everything else is approximate.
Then the type, then who
2026-03-14_invoice_EDF.pdf reads at a glance: when, what, from whom. The order matters: it is the order in which you search.
Avoid capitals and spaces. An underscore between blocks, a hyphen inside a block: 2026-03-14_payslip_ACME.pdf.
What not to put in
- An internal reference number: it means nothing outside the software that produced it.
- “final”, “v2”, “definitive”: the date says which is the latest.
- Characters Windows refuses:
\ / : * ? " < > |, and the namescon,nul,aux,lpt1, reserved for forty years. - Paths that are too long: beyond 260 characters Windows refuses to open the file, and the error message does not say why.
Frequently asked questions
- Should old files be renamed?
- Rarely. A new convention applies to what arrives; reworking ten years of archives costs more than it returns, unless a tool does it for you in one pass.
- What about accents?
- They work everywhere today, with one exception: macOS stores them in a decomposed form, and a file copied between systems can appear twice. If the folder travels, avoid them.