If you've been toiling away for years in your current job, you're probably ready for more challenging work and the pay raise that comes with it. Express your interest in being promoted with a well-constructed cover letter and an updated resume that describe your skills, qualifications and aptitude. Your current employment record and job performance can speak to your ability for higher level responsibilities.
Compose the introduction of your cover letter for a promotion similar to one you'd write for a job with another employer. Use standard business letter format, including your full name, contact information and the proper opening and closing salutations. In your first paragraph include your current title or position, department and how long you've worked for the company. This is basic information that the reader can obtain just by reviewing your personnel file, but it's a sign of courtesy to save the reader time in searching for your employment record.
In the second paragraph of your cover letter, state that you meet the requirements for the promotion. Many employers require that you work for the company at least six months to a year before you apply for another internal position. For example, you could write, "I have been an employee of ABC Mechanics for four years, and I have been in my current position as lead mechanic for 18 months. According to information in the employee handbook about transfers and promotions; I satisfy the requirements for applying for an internal supervisory role."
Again, the reader could just as easily look up your employment record to review your skills and qualifications. But it's up to you to sell yourself for this promotion, so describe your skills and list additional skills you acquired since joining the company. In one to two sentences in this third paragraph, connect your skills set and qualifications to the basic requisites for the new job. For example, if the job posting requires completion of specific on-the-job training or skills, list the required skills that you have and the training completion date or the date on which you acquired those skills.
The advantage you have over external candidates is that you know the company, its policies and procedures, and you are regarded as extremely proficient in your role. Use this to persuade the reader to look at your updated resume. Give the reader a reason to consider you because you are, after all, an insider whose ramp-up time would likely be much shorter than an external candidate. Also, indicate how the working relationships you have formed throughout your tenure prepare you to do well in this new position. An external candidate won't have the breadth and depth of knowledge that's required; therefore, you have a leg up on your competition and you should say so with confidence, not arrogance.
Conclude your cover letter by restating your interest in the promotion. Without overdoing it, indicate how much you enjoy working for the company. Say that you believe you have many more valuable contributions to make in a higher-level position where you could make significant strides in helping the organization reach its goals.