How many letters do I need?

Programs usually ask for two to three, but check each program's requirement.

People who know your work well and can speak in detail, such as professors, research supervisors or employers.

At least four to six weeks before the deadline, and earlier if possible.

What should I give my referees?

Your CV, statement, transcript, a list of programs and deadlines, and reminders of work you did with them.

Can I read my letters?

In many systems you waive the right to see them, which makes them more credible. Check the policy where you apply.

Letters of Recommendation for Graduate School: Who and How to Ask

A letter of recommendation is the one part of your application written by someone else. That is exactly why committees value it. Anyone can say they are hardworking and creative. When a professor or supervisor who has watched you work for months says so, with examples, it carries weight. Good letters do not happen by accident, however. They come from asking the right people, early, and helping them to write something specific and strong.

Practices differ by country, field and program. This guide gives general advice and no guarantee of outcomes. Always follow each program's instructions.

Why letters matter

Recommendation letters help committees understand things that grades and statements cannot show.

Your abilities, such as research, analysis, writing and teamwork.
Your character, including reliability, curiosity and resilience.
Your potential, compared with other students the referee has known.
Context, such as challenges you overcame.

They are especially important for research degrees, where faculty rely on trusted colleagues' judgments. A lukewarm letter can hurt, and a detailed, enthusiastic one can help a lot.

How many and whom to ask

Most programs ask for two or three letters. Some allow more, and some ask for specific types, such as one academic and one professional.

Choose people who:

Know you well, and have seen your work over time.
Can speak in detail, with specific examples.
Have relevant credibility, such as professors in your field or supervisors in a related job.
Will write a positive letter.
Are reliable and will submit on time.

A detailed letter from a lecturer who supervised your project is worth more than a vague letter from a famous professor who barely knows you. Our guide to contacting potential supervisors explains how relationships with faculty develop.

If you have been out of school

Many applicants have been working for years.

Use employers or supervisors who can describe your skills and achievements.
Use a mix of professional and academic referees if you have both.
Reconnect with a former professor and remind them of your work.
Use research or volunteering supervisors, where relevant.

Explain to your referees how long it has been, and give them materials to jog their memory.

When and how to ask

Timing and manner matter.

Ask early. Aim for at least a month or two before the deadline, and earlier at busy times.
Ask in person or by a polite message, and ask whether they feel able to write a strong letter. This gives them an easy way to decline if they cannot.
Explain what you are applying for, and why.
Provide the details in an organized way.
Give the deadline and how the letter is submitted.
Offer to meet to discuss your plans.

If someone hesitates or says they cannot write a strong letter, thank them and ask someone else. A weak letter is worse than none.

What to give your referees

Make their job easy.

Your CV or resume.
Your statement of purpose, or a draft.
Your transcript.
A list of programs and deadlines, with how each program collects letters.
Reminders of your work with them: courses, projects, dates, grades and anything you are proud of.
A short note about your goals and what you hope the letter will emphasize.
Links or instructions for submitting.

Our guide to statement of purpose tips explains how to prepare a statement your referees can read in advance.

What makes a letter strong

Strong letters are:

Specific, with examples and stories, not general praise.
Comparative, placing you among other students the writer has known.
Relevant, addressing skills the program needs.
Honest, with credible detail.
Well written, and well organized.

Generic letters, such as "she is a hardworking student," do little. Specific ones, such as "she redesigned the experimental protocol after noticing a flaw that I had missed," stand out. You cannot write your letter, but you can remind your referee of the specifics.

Waivers and confidentiality

In some systems, you are asked whether to waive the right to see your letters. Waiving is common and often seen as making letters more credible, because writers can be frank. Check the policy where you apply. If you do not waive, be aware that referees may be less candid. Do not pressure referees to show you their letters.

Submission and tracking

Most programs ask referees to submit letters through an online portal.

You enter the referee's email in the application, which triggers a request.
Referees receive a link and upload or write their letter.
You can usually see whether it has been received, but not read it.
Send a polite reminder a week or two before the deadline if a letter has not arrived.

Keep a spreadsheet with each referee, program, deadline and status. If the application asks you to enter referees' emails early, do so well in advance, so that they have time.

Reminders without nagging

Referees are busy. A friendly reminder is appropriate.

Send one gentle reminder about two weeks before the deadline.
Send another a few days before, if necessary.
Offer to resend materials, or to help with the portal.
Thank them when the letter is submitted.

Avoid anything that sounds like pressure. If a letter is late, contact the program to ask about extensions.

If a letter is weak or late

You cannot control what is written, but you can reduce the risk.

Ask referees directly whether they can write a strong letter.
Choose referees who know you.
Give them materials.
If a letter is late, contact the program office, which may allow extensions.
If you suspect a weak letter, consider adding another referee, if the program allows.

International and professional applicants

If your referees are in another country or do not use English, check whether the program accepts letters in other languages, or requires translation. Make sure referees understand the format and the submission portal. For professional programs, ask referees who can speak to leadership, ethics and teamwork.

Thanking your referees

Thank them in person or in writing after they submit.
Tell them the outcome, whether good or bad.
Stay in touch, since you may need them again.

Referees give their time as a favor, and gratitude strengthens the relationship.

A worked example

Imagine a student applying to three PhD programs. In September she asks two professors and a research supervisor in person whether they could write strong letters. All agree. She sends each a folder with her CV, statement, transcript, the three programs' deadlines and a page reminding them of her project, the work she did and a result she is proud of. Each program sends requests through its portal, and she tracks them in a spreadsheet. She sends one gentle reminder ten days before the first deadline and thanks each referee afterward.

Her organization made it easy for referees to write specific, timely letters.

Building relationships early

The best letters come from relationships built over time. Go to office hours, take on projects with faculty or supervisors, ask questions and share your goals. If you are still an undergraduate, start two years before you apply. If you are working, build visible, memorable work with your supervisor and let them know your plans.

What to do if you are short of referees

If you cannot think of enough people, talk to your adviser or the program coordinator. They may suggest who to ask, or allow a different type of reference. A strong letter from a less obvious person is better than a weak letter from the person you expected.

Common mistakes

Asking too late.
Asking people who barely know you.
Not giving referees materials.
Not checking portal instructions.
Nagging referees.
Forgetting to thank them.
Choosing a famous name over someone who knows your work.

A quick checklist

Have I chosen referees who know me and can speak in detail?
Have I asked at least a month or two ahead?
Have I given them a clear package and a list of deadlines?
Have I entered their details in each portal and tracked status?
Have I planned reminders and thanks?

Final thoughts

A good recommendation letter comes from a good relationship and good preparation. Choose referees who know you, ask early and politely and give them everything they need. Track deadlines, remind gently and say thank you. A strong letter can give your application a voice that is not your own.