Writing Conventions | The Rules for Clear Letters

Conventions are the habits readers expect. Follow them and the reader notices only your message; break them and the reader notices you. This page collects the conventions that matter in letters and in most other writing, with the old “rules” that no longer apply marked as such. For spelling and punctuation in detail, see the two companion guides linked at the end.

Conventions of layout

Dates in full: 3 March 2026. Numeric dates are read differently in different countries.
Addresses: yours top right, the reader’s on the left below the date, in a formal letter. One element per line, no commas at line ends.
Greeting: Dear plus the name. Dear Ms Okafor, Dear Dr Lee, Dear Sam Taylor if the gender is unknown, Dear Sir or Madam if the name is unknown. “Dear Sirs” is obsolete. “To whom it may concern” is for open letters and references, not correspondence.
Sign-off: Yours sincerely after a name, Yours faithfully after Sir or Madam. Kind regards and Best wishes in emails and personal letters. Capitalise only the first word.
Paragraphs: one idea each, a blank line between them, no first-line indent in typed letters.
Titles: Mr, Mrs, Ms, Miss, Dr, with no full stop in British usage. Use Ms for a woman unless she has used Mrs or Miss herself.

Conventions of tone

Match the reader. A letter to a company is courteous and plain; a letter to a friend sounds like you. In both, prefer short words to long ones, active sentences to passive ones (“I enclose the receipt”, not “the receipt is enclosed herewith”), and concrete statements to vague ones. Do not use text-message shorthand, emoji or slang in anything formal, and do not use business jargon in anything personal. Avoid sarcasm in writing: without a voice to carry it, it reads as rudeness.

Conventions of grammar that still hold

Complete sentences. Every sentence needs a subject and a verb. Fragments are fine in headlines and informal notes, not in formal letters.
Subjects and verbs agree. “The list of items is enclosed” (the list is), “the items are enclosed”.
Consistent tense. Tell the story in the past tense and your request in the present.
Pronouns that point clearly. If “it” or “they” could refer to two things, repeat the noun.
Apostrophes for possession and contraction only. The company’s reply, the customers’ complaints, it’s (it is) but its (belonging to it). No apostrophes in plurals: CDs, the 1990s, two MPs.
Capital letters for names, not for emphasis. Proper nouns, the first word of a sentence and the start of a greeting. Not “we offer a Full Refund”.

Old rules you can ignore

Several “rules” taught in the past were never rules of English, and following them rigidly produces stiff sentences. Modern style guides, including those of the major UK publishers and the plain-English movement, agree on these:

You may split an infinitive. “To boldly go” is fine. Split it when the sentence reads better that way.
You may end a sentence with a preposition. “That is the department I wrote to” is natural English. “That is the department to which I wrote” is also correct, and more formal; choose by tone.
You may begin a sentence with And or But. Sparingly, for emphasis. Formal letters usually do not need it.
You may use contractions in anything but the most formal writing. “I’m” and “don’t” are normal in emails and personal letters. In a formal complaint, write them out.

Conventions of courtesy

Use the reader’s name correctly, spelled as they spell it. Check it twice.
Thank the reader for something specific when there is something to thank them for; do not thank them “in advance” for doing what you are asking.
State a request as a request (“Please send”), not as an order or a hint.
If you are angry, write the letter, leave it overnight, and remove every adjective before sending.
Reply to letters within a week, even if only to say when a full answer will come.

Numbers, money and abbreviations

Spell out numbers one to nine and use figures from 10 upwards, except in dates, prices and references, which are always figures. Write money as £84.99, with no space, and large sums as £2,500. Write per cent in full in letters. Explain an abbreviation the first time you use it: “the Package Travel Regulations (PTR)”. Common ones such as UK, BBC and VAT need no explanation.

Checking

Spell-checkers catch misspellings, not wrong words: they will pass “their” for “there” and “affect” for “effect”. Read the letter aloud once; the ear catches what the eye slides over. Then let someone else read it. For a letter that matters, print it and read it on paper, where errors show up that screens hide. The spelling guide lists the pairs that cause most trouble.