A cover letters for a CV should be submitted with any job application that requires resumes and CV because cover letters complement and support resumes and CV. You can use cover letters to introduce yourself to potential employers, to explain how you heard about and why you are interested in their companies, to supplement the information in your resumes and CV, and to politely request interviews. Cover letters are formatted the same as are other business letters: a single page with at least 1” margins on all sides; 12-point, single-spaced serif font; and your contact information at the top followed by the date, the contact information of potential employers at the companies to which you are applying, the subject of the letter, and the formal salutation to the potential employers. The remaining information in a cover letter for a CV is divided into three paragraphs (without indentation) that are separated by a single space: the introduction paragraph, the body paragraph, and the conclusion paragraph.
In the introduction paragraph, you briefly introduce yourself, how you heard about the open position, and why you are interested in working for that particular company. For the introduction paragraph, you will need to research information about each company to which you apply, so each application will have its own unique cover letter that you will specifically tailor with information you gather in your research.
In the body paragraph of a cover letter for a CV, you partially explain what qualifies you for the position at the company to which you are applying and how your skills would benefit the company. This information should supplement, not replace, the information you included when writing a CV. You want to tell potential employers enough about yourself so that they are interested in you, but you want to leave room for more explanation so that potential employers will want to call you in for interviews. The body paragraph is also a good place to explain (but not to focus intensely on) any unusual information in your resumes and CV, such as large gaps in employment and unique areas of research. If the quantity of this information and your experience dictates doing so, you could divide the body paragraph into two separate paragraphs. However, you should still try to limit your cover letter to one, single-spaced page because potential employers might discard your resumes and CV before they even read these documents if the first thing they see are long, dense, wordy cover letters with your applications.
In the conclusion paragraph, you briefly summarize the information that you presented before, and you issue a request for action from potential employers (i.e., you ask them to call you in for an interview). You should restate your preferred contact information (email or phone number). You should also politely state that if you are not contacted by a specific date, then you will call to check on the status of your application, which (if done correctly) might entice potential employers to contact you before you contact them.
You should end your cover letter for a CV with a formal farewell, your signature, and your typed name. At the bottom of the letter, you should create an enclosure line stating what documents you are submitting with the cover letter (resumes, CV, etc.).