Study CommonsRead · reason · practise

Daily Read / Canada & Community

Canada & Community · Read a code as a system: find the main idea, sort details by position, and use the rules to decode an example

How Do Canadian Postal Codes Work? Reading the Letters and Digits

Learn what the six characters of a Canadian postal code mean, which first letters belong to Ontario, and what a zero in the middle tells you.

Suggested Grades 3–5329 core-passage words20 questions
What you’ll practiseExplain the parts of a Canadian postal code, use the first letter to name a province or part of Ontario, say what a 0 as the second character means, and name letters that are never used.

Device/browser voice. Pronunciation and availability vary.

Six characters, two parts

Canadian addresses use a postal code. A postal code has six characters, written in the pattern letter, digit, letter, space, digit, letter, digit. One example is L5C 1L7.

The first three characters are called the forward sortation area, or FSA. In L5C 1L7, the FSA is L5C. The last three characters are the local delivery unit, or LDU. Here, the LDU is 1L7.

Every postal code that starts with the same three characters, such as K1A, belongs to one FSA.[2]

The first letter

The first character is a letter that identifies a province or territory. The Northwest Territories and Nunavut share the letter X. Postal codes start with the letter A in Newfoundland and work their way to X in the North.

Ontario is special. For Ontario and Quebec, the first letter also points to a particular part of the province. Ontario postal codes begin with K, L, M, N or P. K means Eastern Ontario, L means Central Ontario, M means Metropolitan Toronto, N means Southwestern Ontario and P means Northern Ontario.

Quebec uses G, H and J. For example, H means Metropolitan Montréal.[1]

Urban or rural?

The second character is a digit. A zero shows a wide-area rural region. Any other digit shows an urban area. K0A 1A0 is an example of a rural postal code.

The third character is a letter again. Together with the first two characters, it identifies a smaller district. That might be a specific rural region, an entire medium-sized city or part of a major city.[1]

Letters that never appear

Six letters never appear in a Canadian postal code: D, F, I, O, Q and U. One source suggests that they look like other characters, such as 0, E, 1 and V. In the first position, W and Z are also left out.

The system began with a test in Ottawa on 1 April 1971. One special code, H0H 0H0, is used for letters to Santa Claus. If you read each zero as the letter O, it spells "Ho ho ho."[3]

Fast lesson

Use these checks before you answer the practice questions.

Use a real address

Find a postal code on a letter, a parcel or your own address. Ask your child to point to the FSA, the LDU and the first letter. Only share your own address if you wish; a made-up one works fine.

Pattern first, meaning second

Have your child say the pattern aloud: letter, digit, letter, digit, letter, digit. Then look at what each position means.

Check the source

The article names only some first letters. For other provinces, a child can use an official list. Ask what else you would need to look up.

Neutral and factual

This reading explains how a code works and does not rate any mail service or policy.

Common mistakes

Thinking the postal code identifies one house only.

Why this fails: The article describes the first three characters as an area and says all codes with the same three characters belong to one FSA.

Thinking N stands for north.

Why this fails: In Ontario, N means Southwestern Ontario. P is the letter for Northern Ontario.

Thinking a 0 means the code is not valid.

Why this fails: A 0 as the second character is allowed and shows a wide-area rural region.

Word Lab

Use the meaning, hear the word, then try it in your own sentence.

postal code

noun phrase

a group of letters and digits that is part of an address to help deliver mail

Write the postal code at the end of the address.

character

noun

a single letter, digit or symbol

A postal code has six characters.

digit

noun

one of the numbers 0 to 9

The second character is a digit.

FSA

noun

forward sortation area: the first three characters of a postal code

K1A is an FSA.

LDU

noun

local delivery unit: the last three characters of a postal code

1L7 is the LDU in L5C 1L7.

province

noun

one of the ten large regions that make up most of Canada

Ontario is a province.

territory

noun

one of Canada's three northern regions

Nunavut is a territory.

rural

adjective

in the countryside, away from large towns and cities

A zero shows a rural region.

urban

adjective

in a city or large town

Any other digit shows an urban area.

district

noun

a smaller area within a city or region

The third character helps name a district.

identify

verb

to show or find out exactly what or where something is

The first letter identifies a province.

pattern

noun

an order in which things repeat or are arranged

The pattern is letter, digit, letter.

Check your understanding

Choose an answer, explain your choice, and then check. Hints and retries are welcome.

Main idea1. What is the article mainly about?
Show answer and explanation

Answer: What the letters and digits in a Canadian postal code tell you. Every section explains a part of the code: its two parts, the first letter, the second digit and the letters left out. Nothing is said about planes, other countries or letter writing.

Detail2. In the postal code L5C 1L7, which part is the FSA?
Show answer and explanation

Answer: L5C. The FSA is L5C, the first three characters. 1L7 is the LDU, the last three. L5 is only two characters, and the whole code includes both the FSA and the LDU.

Detail3. A postal code in Ontario begins with N. Which part of Ontario does N point to?
Show answer and explanation

Answer: Southwestern Ontario. N means Southwestern Ontario. K is Eastern Ontario, P is Northern Ontario and M is Metropolitan Toronto. Students may guess N means north because it is the first letter of the word.

Try the questions here. Public practice does not save a learning record.

Support · Find it in the text

Support · Find it in the text practice

Each answer is in the article. Point to the sentence.

Locate

1. How many characters does a Canadian postal code have?

Locate

2. What do the letters FSA stand for?

Locate

3. Which letter is shared by the Northwest Territories and Nunavut?

Locate

4. Which five letters start Ontario postal codes?

Locate

5. What is the example of a rural postal code?

Locate

6. Which code is used for letters to Santa Claus?

Apply · Decode the code

Apply · Decode the code practice

Use the rules from the article to decode each example.

Decode

7. In M5V 2T6, what does the first letter M show?

Decode

8. In K0A 1A0, is the address urban or rural? How do you know?

Decode

9. Name the FSA and the LDU in P3E 4K9.

Check

10. Is D5A 1B2 a valid pattern? Why or why not?

Choose

11. A code starts with H. Which place is it from according to the article?

  1. Metropolitan Montréal
  2. Southwestern Ontario
Explain

12. Why does the first letter help the postal system?

Reason · Use the ideas

Reason · Use the ideas practice

Apply what you learned to new situations.

Apply

13. A relative lives in a small farming area. What would you expect the second character of their postal code to be?

Apply

14. You see the code V6B 1A1. Can you tell the province from the article?

Reason

15. Why might leaving out the letter O be useful when codes also use the digit 0?

Create

16. Make up a fake postal code that follows the pattern but uses no unused letter.

Research

17. Find out what your own postal code's first letter means.

Practice answer key

  1. 1. Six.
    See 'Six characters, two parts'.
  2. 2. Forward sortation area.
    See 'Six characters, two parts'.
  3. 3. X.
    See 'The first letter'.
  4. 4. K, L, M, N and P.
    See 'The first letter'.
  5. 5. K0A 1A0.
    See 'Urban or rural?'.
  6. 6. H0H 0H0.
    See 'Letters that never appear'.
  7. 7. It shows Metropolitan Toronto, a part of Ontario.
    From 'The first letter'.
  8. 8. Rural, because the second character is 0.
    From 'Urban or rural?'.
  9. 9. FSA: P3E. LDU: 4K9.
    The FSA is the first three characters.
  10. 10. No. The letter D never appears in a Canadian postal code.
    The article lists D, F, I, O, Q and U as never used.
  11. 11. Metropolitan Montréal, in Quebec.
    H is a Quebec letter.
  12. 12. It tells you the province or territory, and in Ontario and Quebec a part of the province. How this helps with mail is an inference.
    The article describes what the letter means. The purpose is an inference.
  13. 13. Likely 0, since 0 shows a wide-area rural region. This is an inference.
    Use the rule, and say when it is an inference.
  14. 14. Not from this article, because it names only some first letters. You would check a full list from a source.
    Saying what a text does not tell you is careful reading.
  15. 15. If O and 0 look alike, leaving out O could avoid mix-ups. One source suggests this reason.
    The reason is suggested by a source, not proven.
  16. 16. Answers vary, for example N2B 3C4. Check letter, digit, letter, digit, letter, digit.
    Use the pattern and the list of unused letters.
  17. 17. Answers depend on where you live. Use an official source.
    Check a real source rather than guessing.

Related skills

What Happens When You Call 9-1-1?What Can You Do at a Public Library?Why Canada Has More Than One Time ZoneReading Library

Put it in your own words

This draft is not saved when you leave or refresh the page.

Check your own explanation

This is self-review, not automatic marking.

Compare with a model response

A Canadian postal code has six characters in the pattern letter, digit, letter, space, digit, letter, digit. The first three characters are the forward sortation area, or FSA, and the last three are the local delivery unit, or LDU. The first letter shows the province or territory, and in Ontario the letters K, L, M, N and P point to different parts of the province. The second character shows whether an area is rural or urban: a 0 shows a wide-area rural region. The letters D, F, I, O, Q and U never appear in a postal code.

Sources and revision notes

Source check: 2026-11-11. Grade guidance is an editorial suggestion, not a standardised reading score.

  1. Innovation, Science and Economic Development Canada — Forward Sortation Area: Definition
  2. Environics Analytics — Canada Post's Postal Geography
  3. Columbia University (Frank da Cruz) — Canadian Postal Codes
  4. Wikipedia — Postal codes in Canada (secondary source for format, 1971 test and the Santa code)
What changed in this edition?

Opened on 2026-11-11. The FSA definition, first letter meanings (province or territory; X shared; K, L, M, N, P in Ontario; G, H, J in Quebec), and the second-digit rule come from the ISED page. The L5C 1L7 FSA and LDU example, A-to-X range, and K0A 1A0 rural example come from Environics Analytics. The six never-used letters D, F, I, O, Q, U and the suggestion that they look like other characters come from the Columbia University page. The six-character format, W and Z also left out in the first position, the 1 April 1971 Ottawa test and H0H 0H0 come from Wikipedia, a secondary source, so those details are lower-confidence. Canada Post's own page could not be opened on 2026-11-11 and is not cited. The questions, practice and activities are this lesson's teaching framing. The reading explains a code and does not support any position on postal service.

Choose another reading