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A. What is activation?

You need to obtain a Keio ID before you use keio.jp.
We call this process "activation".

Read the Terms of Use carefully before activating your ID. If you do not agree to the Terms of Use, you cannot use keio.jp.

B. Restrictions on the Keio ID and password

In principle, a Keio ID that is already registered cannot be changed.
Be sure to enter an appropriate ID when registering.
If the university administration deems the ID to be inappropriate, the ID might be invalidated.

The follows are restrictions on the characters that can be used for the Keio ID and password:

  Length Valid characters Invalid characters
Keio ID 2 to 31 characters - lower case letters (a-z)
- numbers (0-9)
- symbols( . _ - )
(excluding parentheses)
- system reserved words (such as root and postmaster)
- strings used for operation management
- offensive words and strings
- IDs already in use
- IDs starting and/or ending with a symbol
Password 8 to 64 characters - The password must contain 8-64 characters.
- Lowercase letters (a to z)A
- Uppercase letters (A to Z)A
- Numbers (0 to 9)A
- Symbols (!"#$%&'()*+,-./:;<=>?[\]^_`~{}|@ ):
  No other symbols can be used.
  Do not use a password that consists only of characters of the same type.
  Do not use a password that can be guessed easily
  (e.g., do not use your birthday or phone number).
- strings consisting of only the same type of characters or the same character.
- strings others can easily guess, such as your telephone number
- strings that are identical to your login name, or which are the reverse of your login name.
- general nouns and proper nouns, including names of people
- strings identical to the key arrangement on the keyboard (such as qwerty)
- Passwords leakage of which has been confirmed in the past


Keio ID

The Keio ID is case-insensitive, and all letters are treated as lowercase.


  1. The maximum password length is 64 characters (when a password of 65 characters or more is entered, the 65th and subsequent characters will be truncated).
  2. The minimum password length is 8 characters.
  3. Four types of characters are allowed (password characters are case-sensitive.).
    • English capital letters
    • English small letters
    • Numbers
    • Space character (one-byte space), and symbols: !"#$%&'()*+,-./:;<=>?[\]^_`~{}|@
  4. There are following restrictions on the types of characters that can be used depending on the password length.
    1. 8 to 15 characters: combinations of at least 3 types
    2. 16 to 31 characters: combinations of at least two types
    3. 32 or more characters: combinations of one or more types
  5. You cannot set up the same email account (the part before "@") as your Keio ID.
  6. You cannot set up the same email account (the part before @) as your old Keio ID (subdomain).

You can register any Keio ID and password within the abovementioned restrictions.

C. Activation

Last-Modified: February 24, 2023

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