What is another word for not allowed?

Here are some words that can be used instead of "not allowed," depending on the context:

Formal:

* Prohibited

* Forbidden

* Restricted

* Off-limits

* Unauthorized

* Unpermitted

* Disallowed

* Exempted (in the sense of being excluded from permission)

Informal:

* Banned

* Out of bounds

* No can do

* Not permitted

* Against the rules

* Not okay

Other:

* Illegal (if it breaks a law)

* Unacceptable (if it's considered inappropriate)

* Against the policy (if it violates a specific policy)

The best choice will depend on the specific situation and the level of formality you want to convey.