The passport scan you need for a visa application at 11pm is either in a folder you can find or it does not exist. Building that folder takes one evening, and the version you build properly also survives a flooded flat, a dead laptop and a locked-out cloud account.
Decide what must survive, and for how long
Start with the documents that are expensive or slow to replace: passport, national ID card, birth and marriage certificates, property deeds, tenancy agreements, insurance policies, pension statements, wills, vaccination records and the last three years of tax filings.
Retention periods differ, and keeping everything forever creates its own mess. The US Internal Revenue Service, for example, expects three years of records for a normal return, six for a claim about bad debt, and seven when income was understated by more than 25% — irs.gov sets out the full table. Property deeds, wills and certificates should be kept indefinitely in original paper form, with a digital copy as the working reference rather than the record itself.
Scan at 300 dpi, name it by date, keep it as PDF
A phone camera is enough if you hold it steady and use a scanner app rather than the camera roll. Apple’s Notes app has Scan Documents built in; Google Drive has a scan button in the floating + menu; both crop the page, correct perspective and export a multi-page PDF.
Set 300 dpi for anything A4 or smaller — that is the threshold most government portals and banks accept, and it keeps text legible when zoomed. Choose greyscale unless a stamp, signature or photograph matters, which cuts the file size by roughly two-thirds compared with colour. Save as PDF, not JPG: a single PDF per document stays in order, and PDFs keep the text searchable if the app adds an OCR layer.
Name files so that alphabetical order equals chronological order: 2026-03-14_passport_expiry-2036.pdf beats IMG_4821.pdf every time. Use one folder per person, plus shared folders for “Home” and “Money”, and keep a plain text index listing what each document is and where the paper original lives. The full workflow for phone scanning, including multi-page handling, is in scanning documents with your phone.
Three copies, two kinds of media, one in another building
One copy is a single point of failure no matter how tidy the folder is. The working arrangement that survives most accidents: the folder on the laptop you use, a mirror on an external drive that stays in the flat, and a third copy somewhere else entirely — cloud storage or a relative’s house.
Free tiers cover it: Google Drive gives 15 GB, OneDrive 5 GB, iCloud 5 GB with 50 GB at about $0.99 a month. A document folder of 400 PDFs at 1–2 MB each is under 1 GB, so 15 GB is plenty unless you also store video.
The off-site copy is the one people skip, and the one that matters when the failure is a fire, a theft or ransomware that encrypts every drive plugged into the machine. If you prefer the physical route, a USB drive in a drawer at a parent’s house works, provided you refresh it every few months. Whatever you choose, check it: a drive unplugged for two years is a guess, not a backup. The same discipline applied to phones is covered in backing up your phone.
Encrypt the folder, and store the key where you can reach it
Identity documents are the raw material of fraud, so an unencrypted folder in a shared cloud drive is worse than a paper file in a locked drawer. Encrypt before uploading, not after.
Three options, in order of effort: 7-Zip’s AES-256 archive (Windows, free, works everywhere); a VeraCrypt container that mounts as a drive letter; or full-disk encryption built into the OS — BitLocker on Windows Pro, FileVault on macOS, default encryption on modern Android and iOS. Full-disk encryption protects the laptop if it is stolen; only the archive or container protects the files once they are uploaded.
Use a passphrase of four to six unrelated words rather than a mangled password, and store it in a password manager with a written copy in a sealed envelope. If the key exists only in your head and the folder is the only copy, encryption has converted a backup into a permanent loss. The habits in password manager tips that actually stick cover the recovery side, including what happens when the phone holding your second factor is lost.
Rehearse the restore, and put expiries on a calendar
Twice a year, pick one document you have not opened since it was filed, download it on a different device, and open it. Files that decrypt on the machine that created them can still fail elsewhere because of a missing password, a truncated upload or a container that never finished copying. Ten minutes of rehearsal is the difference between a backup and a belief.
Then add the dates that catch people out: passport validity (many countries require six months remaining on arrival), visa expiry, insurance renewal, vehicle registration, and the review date on a will. A single calendar entry per document, set twelve months ahead, costs nothing and prevents the scenario where a ten-year passport turns out to have eight months left on it two weeks before a flight.
Finally, tell one other person where the folder lives and how to open it. A backup nobody else can reach is useless to the family member who needs the insurance policy while you are in hospital — usually the exact moment all of this was for.