Save it yourself
TL, DR: Save your bank statements & check images.
Today was a pretty tedious day. I had to download all of my bank statements and save each (and every) image of a check I wrote in the last 2 years. Why? Because of two important things I want to share with you so you can avoid problems in the future. As always, I'm not a lawyer or financial consultant.
First, you should keep as many of your financial records as possible. Preferably in exacting detail. The reason is that you never know when you might need to demonstrate something important. This can be
- to defend yourself from a lawsuit,
- to justify something you said (like to the IRS or a judge),
- to prove that you spent money on something you deserve a tax credit for,
- to prove you owned something at a certain time or paid for it in the right way.
Second, your bank is not your cold storage. They might keep statements for several years, but not forever and- in some cases- not for you, but for their own records. Check images are worse because they're bigger files that're more expensive to keep around. Your bank probably lists your checks in your statements as "CHECK #99010 2014/05/01 $2,300" and that's not going to help you prove that you spent that $2,300 on a home repair that increased your cost basis. In my case, Charles Schwab keeps my statements for 10 years but check images are only around for 2 years.
Stay organized and diligent. If it takes 2 hours every January to scrape down a year's worth of files and images from all your banks, that's annoying. But if that effort saves you from a serious loss or allows you to take a tax credit on something big (like a car, house, boat, or investment) then it’s just too important to ignore.