What it usually means
A letter is a message that travels. Unlike a conversation, it can be written slowly, read alone, kept for years, or never sent at all. Dreams about letters usually draw on those qualities: news that is coming, something that needs to be said, a message that has not yet been opened.
Receiving a letter is the most common form. The feeling decides the meaning: excitement suggests hope for news or recognition, dread suggests fear of judgement, bad news or consequences. Many such dreams come when a person is waiting for a decision — a job, an exam result, a medical test, a reply from someone who matters.
Writing a letter is about expression. A dream in which you write — especially a letter you cannot finish, or one you are afraid to send — often points to something you want to say in waking life and have not yet found the right form or courage for.
Old letters belong to memory. Finding a bundle of letters, rereading something from long ago, or receiving a letter from the past often accompanies a time of reflection, when old relationships and old versions of yourself come back into view.
Letters can also be secrets. A letter hidden, intercepted, read by the wrong person: such dreams tend to be about privacy, trust and what you would rather others did not know.
Most people now send emails and messages rather than letters, yet paper letters keep appearing in dreams. That alone says something: the dream reaches for the older, weightier form when the message matters more than a quick reply would suggest.
What changes the meaning
Receiving a letter. News on the way; a message you are waiting for, or one you fear.
An unopened letter. Something you know is there but have not faced yet.
A letter you cannot read. A message not yet understood; information that is still unclear.
Writing a letter. Something you need to say; a wish to explain yourself.
Not sending a letter. Words held back; hesitation about revealing your feelings.
A love letter. Longing, affection, or a wish to be told you are loved.
A letter from someone who has died. Grief and a wish for their words; often a message from your own memory of them.
Losing a letter. A missed chance to communicate; fear that something important has gone astray.
Someone reading your letters. Fear of exposure; private matters coming to light.
A letter with bad news. Anxiety about a pending outcome.
A pile of unanswered letters. Obligations accumulating; relationships neglected.
Burning a letter. Letting go of the past, or destroying evidence of a feeling.
When it keeps coming back
Recurring letter dreams often appear during long waits — for visas, results, decisions, replies — when life is on hold until something arrives.
They also return when an important conversation has been postponed. The unwritten letter keeps reappearing until the words are said, in some form.
If you keep dreaming of a letter you cannot read, try writing on waking what you think it said. People are often surprised by how much they already know.
In Jungian terms
The friendship between Jung and Freud began with letters in 1906 and largely ended in them. Over seven years they exchanged hundreds, full of ideas, admiration and growing tension. In December 1912 Jung wrote that Freud's habit of treating his pupils like patients was a mistake; a few weeks later Freud proposed that they give up their personal relationship altogether. Much of what the two could not say face to face found its way onto paper.
Jungian readers see dream letters in that light. A letter is often the form in which something difficult can finally be said — slowly, alone, with time to choose the words.
That gives letter dreams a practical use. A letter written on waking, even one that is never sent, is often the simplest way to find out what the dream was trying to deliver.