Question from Software Recommendations on Stack Exchange:
I want a site, where I can put some documents and a password, or a list of passwords. The site should keep documents secret while I enter the passwords periodically, removing them after the last password or publishing them if passwords are not being entered.
It should be like a dead-man’s switch.
[Read, comment, and vote on my answer at Stack Exchange]
Unlike most software recommendations, it is impossible to recommend a service here and confidently say that it works: to know if it worked, you would have to be dead, right?
At any rate, there are many websites that offer free and/or paid versions of this. One of the major problems is that many of those websites have gone out of business, so selecting a website can be difficult because you don’t know if the site will still exist when you die.
Nevertheless, there are some services that have been around for a little while and have adopted a simple enough business model that they might survive. (Pardon the pun.)
A similar idea to your question is “Trusted Contacts” If you were to die, your Google and Facebook accounts would presumably no longer have any activity. If you have pre-arranged a list of trusted contacts with each company, then those companies will then allow your trusted contact(s) to access your account. See Google’s explanation.
Facebook’s feature is really designed to help you, while you are alive, regain access to your account if you are locked out. But the same process could certainly be used by your estate to get access to your Facebook account.
The low-tech method is to hire an estate lawyer.