An attachment letter, also referred to as a letter of internship, is a cover letter for students looking to build career experience, meet mentors and gain opportunities for post-education jobs. A student will outline their interest in an internship at a particular company. The internship market is highly competitive. Students must effectively sell their qualifications when writing an attachment letter to garner corporate attention.

Format the Letter 

An attachment letter is a business letter that follows standard business formatting guidelines. Choose a professional font such as Arial, Courier or Times New Roman. Make the font size at least 10, but 11 or 12 is preferred. Don't use fonts bigger than 12. Business letters use block formatting; a block is a section of information such as contact information or a new paragraph. All blocks are aligned on the left margin with no indentation of paragraphs. Pages have one-inch margins on all sides. Block formatting uses one line space between paragraph blocks.

Introduce Yourself 

The attachment letter introduces the student to the company's human resources division. Include a reference or subject line, such as "Re: Application for Research Attachment," in bold type above the body of the letter. Though not required, the reference line is highly recommended to get the letter to the right person faster.

Letter basics concisely state a student's major, minor and the year of study. Include any pertinent work or research experience. Specific skills, experiences or classes differentiate students with more skills than others. Note any other work experience that demonstrates professionalism or specific skills. Professional outside work might include part-time work at a bursar's office or a local bank. Think twice about including experience as a camp counselor or waitress in the letter, unless it directly relates to the sought internship.

Stand Out From the Crowd

There is a lot of competition for internships, which is similar to job market competition. Once you outline the contents of the letter, research the company and connect the dots for the human resources director. This means stating why you desire the internship. Express how you are the best candidate based on your level of education, specific skills and pertinent experience. Take the time to explain how the company's internship will build needed skills through practical implementation of studied theories.

Add Enclosures 

The attachment letter servers the same purpose as the job seeker's cover letter. Job seekers naturally include a resume as an enclosure with the cover letter. The same is true with attachment letters, giving more details about work history and education. Some applicants benefit from including a published article or a letter of recommendation – denote "Enclosures" under your name at the end.