How To Write A Formal Excuse Letter For College . If you were absent more than 3. If you do not know one or more of these facts, your letter will more likely be rejected. Formal Excuse Letters (10+ FREE Samples & Templates) purshoLOGY from www.purshology.com A clear subject line stating the reason for applying for leave. Reasons for this can involve anything from illness to attending a family trip. Please see the template for each situation and my suggestions for its content.