In regard to / In regards to
UsageUse in regard to without s, or use the plainer regarding. Avoid in regards to in formal writing.
In regard to
Use when
You need a formal phrase meaning in relation to or about.
Example
“I am writing in regard to your application.”
In regards to
Use when
Avoid this blended form in formal workplace writing; use in regard to or regarding.
Example
“Replace 'in regards to your application' with 'regarding your application'.”
Quick check
in regards to, in regard of, regarding to
Usage note
In regards to occurs in modern informal usage, but many formal style authorities still prefer singular regard in this expression.