UK · Thailand · South Korea — plain-English research, July 2026. Not legal advice.
The one thing that decides everything: authentication. Every court here allows digital messages in. Then it asks the real question — “how do we know this is genuine and not edited or invented?” If you can’t answer that, the evidence is nearly worthless. A lone screenshot is the weakest form there is, because anyone can fake one.
🇬🇧United Kingdom — very receptive to message evidence. But screenshots are “the most common, and most commonly rejected” form. Courts want the full Export Chat file or a forensic extraction with metadata attached.
🇹🇭Thailand — the Electronic Transactions Act 2001 (Section 11) says evidence can’t be rejected just for being electronic. But the same law makes the court weigh how reliably it was created, stored, and whether the sender can be properly identified — through metadata, internet-provider records, or a witness. Unauthenticated screenshots have been found not enough, especially in defamation cases.
🇰🇷South Korea — the strictest of the three on integrity. Its Criminal Procedure Act (Article 313) plus Supreme Court rulings require you to prove the copy is identical to the original — and the preferred way to prove it is literally hash-value comparison and forensic verification. Korea cares more about a provable integrity trail than anywhere else.
An archive you keep yourself is excellent for finding and preserving — knowing what was said, when, by whom, and never losing it. But be clear-eyed: on its own it has the same weakness as a screenshot. You control it, so the other side just says “you could’ve edited your own database.” It isn’t self-proving.
So treat the archive as the index, not the proof. It tells you what exists and where. The proof itself comes from:
① Preserving the original — don’t delete the chat, don’t wipe the phone. The phone
is the primary source a forensic examiner verifies against.
② A forensic export + hash from that original device.
③ For anything serious, the platform’s own server records via a lawyer’s court order —
the version nobody can dispute.
One way to give a self-kept archive real credibility instead of none: hash-stamp every message and anchor those fingerprints somewhere timestamped and outside your control (e.g. a dated, append-only record). That creates a trail proving the messages existed in exactly that form on that date — you couldn’t have altered them after the fact. It won’t beat a forensic phone extraction, but it turns “you made this up” into a much harder argument — and it’s exactly the kind of integrity proof Korea asks for.
🇬🇧 Truescreen — WhatsApp evidence in court (2026)
🇬🇧 Eddison Cogan — Texts, emails & WhatsApp as evidence
🇹🇭 Silk Legal — Electronic evidence under Thai law
🇹🇭 Formichella & Sritawat — Evidence in Thai defamation cases
🇰🇷 Korea — Criminal Procedure Act (English)
🇰🇷 Lexology — Korean Supreme Court on duplicated evidence & hashes