I often see “dependant” used incorrectly.

Problem:
The preferred use of “dependant” is as a noun, not as an adjective.

Explanation:
Some dictionaries indicate that “dependent” and “dependant” are synonyms.

However, other dictionaries indicate that the preferred use of “dependent” is as an adjective and that the preferred use of “dependant” is as a noun.

One way to remember this distinction is to think of “confidant”, which is a noun, versus “confident”, which is an adjective.

Solution:
Use “dependent” when you’re modifying a noun to indicate contingent or relying on something or someone else; use “dependant” when you’re talking about a person who relies on or is supported by another.