The convenience you get from online banking and paperless financial statements can lead to an enormous inconvenience for your heirs: the chore of having to track down your assets after you have passed away.

Trying to find a decedent’s assets has always required a certain amount of detective work. Before the days of online banking, heirs had to sift through files and have future mail forwarded to the estate’s executor to locate accounts. But since there’s often no paper trail for online accounts, heirs can be left in the dark unless you leave behind a detailed list of what you have and where it can be found. Unless you take steps to document your financial affairs, the added difficulty of finding your assets will mean large fees must be paid to professionals to look for them or, in some cases, that assets can never be accounted for and properly allocated.

You might think there’s a way simply to search for all the assets someone has using their Social Security number—after all, you need to provide one to open just about any type of account these days. But although the executor of a will could ask individual banks and other institutions to check for any accounts or unclaimed property using the decedent’s Social Security number, there’s no national database. So, the executor needs a place to start when searching for assets.

Of course, a search for assets is easier if an account pays interest or dividends every year, since a description of the account and institution will be listed as income sources in the decedent’s tax returns (assuming the income was properly claimed). But if you hold a long-term CD, bond, stock shares, or other assets that haven’t realized any gains and won’t for some time, they won’t be listed on past tax returns and heirs may not know of their existence.

So, what should you do to prevent this mess? Unfortunately, even in your paperless financial world, you may need to write down some things. Begin by making a list of the following:

  • If you use them—and you should—the passwords to log on to any personal computers you have;
  • Institutions where you have any type of active banking, brokerage, retirement, or pension accounts;
  • Companies from which you have bought life insurance;
  • Locations of safe-deposit boxes;
  • Real-estate properties you own or for which you have an equitable interest;
  • Where copies of your tax returns can be found, as well as where you stash your will, birth certificate, Social Security card, marriage certificate, divorce decrees, closing documents for real-estate transactions, and other key documents; and
  • Names of any attorneys, insurance agents, and accountants with whom you have worked and who have knowledge of your assets.

For accounts, just list the institution and a brief description of the type of account you hold with each. Don’t include in this list account numbers or user IDs and passwords that would let someone access your accounts. Doing so is too risky, and in any case, this information won’t be needed by your heirs, since they will be able to petition the financial institutions to have your assets included for probate by having your will’s executor simply provide your Social Security number, a copy of your death certificate, and other information.

Keep your up-to-date list in a safe place, such as, a fire-resistant document box or a safe-deposit box, and give a copy of it to the executor of your will, your attorney, a direct heir, or a close friend.

As an alternative to a paper list, you can use various financial software packages that help organize assets. For example, with Quicken’s site, you enter details about all the online accounts you have and it maintains for you in a one-stop spot a view of all your online accounts and balances. Like an online banking site, your information is protected by a user ID, password, and encryption. But unlike a bank’s site, your information is held for you in a “read-only” form, so funds can’t be transferred out by anyone using it.

Of course, if you go the route of using software to organize and list your account information, you’ll still need to set up a way to let heirs know where to find it—and how to access it.