Once a person asked me if it was okay to talk about their salary history with an employer during an interview. They were concerned about discussing their history because it was a little low and they thought it would have a negative effect on their salary negotiation. They were wondering how they could avoid the topic with the employer until the right time. My rule is to never be dishonest with an employer, however it is a good idea to avoid this topic until you have nearly closed the deal with getting the job.
In the past, I have been in the same situation, and have been pressured for a response to the tough questions on salary. My approach has been as follows.
1) The approach I would take would be to ask to table the question until later in the interview or for another day. It is important to me that we have first come to a common understanding on the roles and responsibilities of the job, and also, the type of experience I bring to the job, and what I will be contributing to the new company. I would prefer to be paid in line with the current job market and within the companies standards for this role.
2) If I am pressured for an answer in an interview where the request is to provide my previous salary, I set out the total value of what I expect the compensation package will hopefully include. That is cash value for the time and effort (salary), list the benefits in as much detail as I can, how much holiday, and other working conditions such as flex time, or time off in place of worked overtime. I also prefer to reiterate that the job I am looking towards is not with the same company and thus my previous earnings not very relevant. In reality, there are so many things to consider, such as home life balance, health benefits, vacations, overtime, etc,etc, that factor in. What is most important to me is that my salary will be aligned within a margin of my past job, and does the package I am offered match what is reasonable for the current job market which can be totally different.
3) It is important for me to be aware before going into any interview what the standard salary range is for that position. I also want determine where my overall percentile would fall within that range. The vast majority of people are not at the top end of the salary range, so unless I know I have been a superstar, which I usually strive towards, then I wouldn't recommend expecting the absolute maximum salary, unless I know I can explain why I am worth it. This is almost always confirmed by reference checks, and also, when starting the new job, it will be obvious if I am not in the 98th percentile. The goal is to be generous with your self evaluation but honest if you are not at the total superstar ranking.
4) No matter what you made at your previous jobs, your expectation should be set at the fair market value for the job in your region. You may have earned less money in the past than the current expectations, possibly even a lot less. The reasons are not relevant to the new job, and therefore you would prefer to be within the companies fair range. Aim to make it clear to the new employer that you want salary negotiations to be fair, regardless of your past salary history.
5) If you do give in and tell them your past salary, make sure you clearly express that you expect to be paid respectably, and you just don't want to be taken advantage of. Explain what you do know about the job market at that time. Most employers will respect you for expressing your expectation for your reasonable salary. Just remember salary negotiation is not supposed to be an offensive situation where you are demanding. Remember to be clear in your negotiations but respectful in your dealings with the recruiting manager.
Whatever you to, be completely truthful during interviews. The employer has many ways of getting information and they will find out your true salary history if they are so determined. They will also learn about your past performance, and they may even ask you to produce a pay stub to prove your past salary. Remember you're a highly skilled worker, and you bring a lot of value to the position. You just need the skills to communicate that value clearly and effectively to the new employer.