A semi-formal letter goes to someone you know but aren't friends with — a landlord, a neighbour, your manager. This is the register most candidates get wrong: polite and respectful, but warmer than a letter to a stranger. 'Dear Mr Davies' with 'Yours sincerely', contractions used sparingly. The letters below all sit in that middle zone.
The one rule
You know the name, not the person. “Dear Mr Davies” with “Yours sincerely” — polite, warm, no slang.
On test day
It's one of the recognised Task 1 formats, so it's fair game on test day — but you can't reliably predict which one you'll be given. Treat every format as likely and practise across all of them rather than betting on a single type.
Templates
Learn the shape, not a script. A reliable structure for semi-formal letter questions saves planning time, but a memorised answer bolted onto the wrong prompt is penalised. Adapt the structure to the exact question in front of you.
Marking
Against the four official IELTS Writing criteria — task achievement, coherence and cohesion, lexical resource, and grammatical range and accuracy. Getting the format right mainly protects your task achievement score; the other three come down to your language.
Practice volume
Enough to make the format automatic, then stop drilling it in isolation. Once you can structure a semi-formal letter response without thinking, your time is better spent on the language criteria that actually move your band.
More Task 1 General Training types
Attempt any semi-formal letter question in the exam workspace — 20 minutes on the clock, then a band for all four criteria in about 60 seconds. Starts with a 3-day free trial.
“A letter applying to volunteer at a local charity shop”