Why Do Employers Seek Salary Histories?

Queanie writes:
When a potential employer asks for a resume with salary history or salary application
what does that mean exactly and what are they looking for?

The Career Doctor responds:
Employers use a salary history request for a number of different reasons. Most often with a salary history employers are examining the frequency and size of your raises and promotions. Employers want to see a natural progression in terms of jobs promotions and accomplishments as well as increases in your salary.
Requests for a salary history put job-seekers at a distinct disadvantage because you are providing the employer with very valuable information and getting nothing in return (unless you feel being considered for the position as something of value). This information becomes critical if you become the applicant that the employer wants to hire because with your salary history the employer can lowball your job offer offering you a salary that is higher than your present salary (but not at the level you want). Your negotiation ability is severely limited. And for job-seekers making a major career change or jump past salary becomes even less important.
What can you do when asked for a salary history? First you need to decide whether you even want the job — whether you want to work for a company that would base even a part of their hiring decision on not what you are worth to the company but on what you have been paid in the past.
Assuming you do still do want to work for the employer you have a number of options.
Most importantly though do NOT put your salary information on your resume.
Create a separate salary history page (similar to a reference page) that matches the
format and look of your resume.
I recommend you read my article Responding to
Requests for Salary Requirements or Salary Histories: Strategies and Suggestions
This article gives you a good overview and provides you with a couple sample salary history formats.
One final piece of advice: Be truthful in your reporting of your salary history.