In the US, the IRS can audit your taxes going back at least seven years. So, you should keep at least seven years worth of the documents that you might need to

In the US, the IRS can audit your taxes going back at least seven years. So, you should keep at least seven years worth of the documents that you might need to produce during an audit. And there are some important documents you want to keep longer than that -- birth certificates, wedding certificates, death certificates, documentation around the house you buy, documentation around your car, any personal health documents you keep, etc.... So, you'll want to have electronic copies of all that, and ideally backed up to an offsite location, in case you have a fire in your house. If you at least have electronic copies of those documents, even if you lose the original document in a fire, there's a good chance you can use that information to get new certified copies sent to you by the appropriate city/state government in question. So, yeah, this can become a thing that needs to be carefully monitored and managed over the decades.