The easiest way to prove that you worked for a former employer is to take something when you leave.

Sort of like taking a bath towel from a fancy hotel as a souvinier.

For example, if you worked for Enron, you might think about taking the big "E" off the front of the building.

Or WAMU, you might think about taking your computer with you when you leave. Be sure it has the property tag still on it along with lots of customer files.

Another way to prove you worked at a former company might be to keep clippings of the newspaper articles describing how you got your revenge. But keep it lighthearted. No firebombings or anything.

I received a comment in mail from another reader:

I was looking for similar information for another purpose and learned that a state Employment Security Department office would provide salary history at no charge The form for the self request for records is this web page: http://www.esd.wa.gov/newsandinformation/formsandpubs/request-records-self.pdf. The resulting report went back into the late 70’s. My situation was complicated by a merger followed by a sale of properties. Data related to a division that survived the sale of properties had the new merger name. Another division that merged and was later sold after the merger had the latest company name.

There are several ways to prove employment after a company has folded, but some of it does require being proactive andassuming that every employer for whom you work will go out of business or not be able to verify your information. Here a few ideas:

1. A copy of your last pay check stub or end-of-the year stubs with your year-to-date earnings on it
2. A copy of your W-2s for the last 7-10 years
3. Staying in touch once a year with ex-coworkers and ex-bosses--not just when you need something from them--so you have their most current contact information...and just to be friendly! (Offer your help, too.)
4. A copy of a Web page that links you to your past employer, such as in a news article or your name and title posted on their Web site
5. Your past business card
6. A copy of your offer letter and separation or resignation letter
7. A copy of your annual reviews, company trainings, or commendations
8. Non-confidential email commendations
9. Getting network connection recommendations on LinkedIn

I'm very late to this debate but I was just consulting someone about this issue a few days ago so I thought I'd add my 2 cents for people still looking for advice. I've worked for hiring agencies and as a hiring manager. Further, I've also worked for a company in Connecticut that went out of business over a decade ago so I've been there personally.

You have to keep that information on your resume if less than 10 years have passed so you don't have any big gaps in your employment.

However, if more than 10 years have passed and you've had steady employment (and good references) during that period, it would be the extreme situation to have a company request any information about that job. Most hiring managers don't expect that you'll still have references from a job you had over a decade ago - it's expected that after 10 years you have probably lost contact with old references (and most references don't expect to be bothered for information about someone they knew over 10 years ago!). I also wouldn't expect a hiring manager to make anyone go through the time and expense of producing tax information or work product from that time period - 3 to 7 years is the maximum amount of time many tax professionals recommend keeping tax records (even the IRS has a period of limitations). I've heard of some people producing a Social Security record of their past work history but those records do have some history of containing incomplete or incorrect information.

So to make my point simple - if the company went out of business within 10 years you should still be expected to provide references (hopefully you can keep in touch on LinkedIn). If the company went out of business over 10 years ago, I don't think it's reasonable or pertinent to expect you to provide references from a job that old.

I've been asked to serve as a reference in the past. I would find it very bothersome for someone I knew over a decade ago to still be using my name as a reference - especially when we've lost touch over those years. Accordingly, it's a waste of time for a hiring manager to expect references from jobs that are very old - these won't be good samples of your current work product anyway.