How Long Should a Letter Be? The Ideal Length for Every Situation

People rarely write letters that are too short. They write letters that are too long.

When the stakes feel high, complaints, job applications, legal issues, appeals, people add detail after detail, hoping more words will equal more power. In reality, the opposite usually happens. Overwriting weakens clarity, buries your request, and makes the reader work harder than they should.

If you’ve ever wondered about letter length in the UK, or asked yourself how long should a formal letter be, this guide explains what actually works, and why.

Why shorter letters usually outperform longer ones

Decision-makers read under pressure. Councils, employers, solicitors, HR teams, and complaints handlers all process large volumes of correspondence.

When a letter is too long, three things tend to happen:

• Key points get missed

• The reader skims instead of reading properly

• The request becomes unclear

  
  

The UK Government Digital Service writing guidance stresses that clear, concise communication leads to better outcomes in official correspondence. Overlong writing creates friction where none is needed.

Shorter letters signal confidence. Long letters often signal uncertainty.

The ideal letter length by situation

There is no single perfect length for every letter, but there are strong patterns across UK institutions.

Complaint letters

Ideal length: 1 page, around 300 to 500 words

Complaint handlers look for facts, timelines, and a clear outcome. They do not need emotional backstory repeated multiple times.

A strong complaint letter should include:

• What happened

• When it happened

• What you have already done

• What you want to happen next

  
  

Citizens Advice recommends keeping complaint letters focused and structured so they can be assessed quickly.

If your complaint runs beyond a page, it usually means the structure needs tightening, not that the issue is too complex.

Job application and cover letters

Ideal length: Half a page to one page, around 250 to 400 words

Recruiters often spend less than a minute scanning a cover letter. They are not looking for your full history, they are looking for relevance.

According to the National Careers Service, cover letters should be concise, targeted, and easy to scan.

If your letter is longer than the job description, it is too long.

Appeal letters

Ideal length: 1 page, up to 600 words in complex cases

Appeals require slightly more detail because decisions must be reviewed against evidence. Even so, clarity matters more than volume.

The key is separation:

• Facts first

• Reasoning second

• Request last

  
  

ACAS guidance on appeals highlights the importance of clear, written explanations rather than emotional argument.

Long appeals fail when they mix emotion, evidence, and opinion into a single block of text.

Legal or formal letters

Ideal length: 1 to 2 pages, only when necessary

Legal letters can be longer, but only when structure is tight and purpose is clear. Even solicitors aim for brevity because precision matters more than persuasion.

The Law Society emphasises clarity and proportionality in legal communication.

If a legal letter feels rambling, it weakens your position rather than strengthening it.

Why people overwrite when they are nervous

Overwriting is rarely about the reader. It is about the writer.

People add extra explanation because they fear:

• Not being believed

• Being misunderstood

• Being ignored

  
  

Ironically, the longer the letter becomes, the more likely it is to be skimmed, delayed, or dismissed.

Clear letters show confidence. Confident letters get results.

How to keep your letter the right length

Before sending any letter, ask yourself:

• Can I explain this in one page

• Does every paragraph serve a purpose

• Is my request obvious within the first 10 seconds of reading

  
  

If the answer to any of these is no, the letter needs editing.

The Plain English Campaign consistently finds that shorter, simpler letters are more persuasive and more likely to be acted on.

When longer letters are justified

Longer letters are appropriate when:

• You are responding to formal allegations

• You are submitting evidence-heavy appeals

• You are instructed to provide detailed statements

  
  

Even then, length should come from evidence, not repetition.

Attachments exist for a reason. Your letter should guide the reader, not overwhelm them.

The bottom line on letter length in the UK

If you are asking how long a formal letter should be, the answer is usually: as short as possible, but long enough to be clear.

Most effective letters are:

• One page

• Structured

• Calm

• Direct

  
  

They respect the reader’s time and make action easy.

How LetterLab helps you get the length right

At LetterLab, we see the same problem every day. Good points buried under too many words.

Our UK letter writing service focuses on clarity, structure, and impact. We cut what weakens your message and keep what moves it forward.

You can send us your first 120 words for free and see how much stronger your letter becomes when length stops being a liability and starts working in your favour.

Additional resources

• UK Government Digital Service – Writing for GOV.UK

• National Careers Service – Cover Letter Advice

• ACAS – Appeals and Formal Procedures

• Law Society – Client Communication Guidance