As Lake Forest, Ill., economist Mike Moebs planned for his marriage last year, his lawyer pressed him for a complete list of assets.

Initially, the frequent-flier miles detailed in his online travel records didn't even cross Moebs' mind until his family law attorney recognized the value of an asset Moebs largely manages online.

"We gave a lot of thought to the things that I own," said the chief executive of Moebs Services. "I've flown, just on American Airlines, more than 3 million miles, and I have a half a million miles I haven't used."

To prepare for the worst, Moebs also has created an inventory of user names, passwords and answers to security questions for more than 50 accounts, including online bank and investment records, and billing setups for credit cards and phone bills. His family and close business colleagues can access them if he dies prematurely or is incapacitated.

Family heirlooms and records aren't what they used to be. Nowadays, everything from photos and music to financial statements and tax documents are increasingly likely to be created, stored or accessed online. "I'm revamping my personal and business trusts to include all digital assets and what I want done with them," Moebs said.

He appears to be far ahead of the curve. Estate planners, lawyers and surveys indicate that few people have begun revising their family and estate plans to keep pace with the new reality of digital assets and online accounts.

In a recent survey by BMO Retirement Institute, more than half of respondents age 45 and older with digital property believe it's very or somewhat important to put plans in place for their personal and financial online assets, yet 57 percent of them haven't made such provisions.

When asked why they've failed to do so, the two most common answers, overwhelmingly, were "didn't think of it" and "I don't think it's necessary."

Chicago lawyer Richard Magnone suggests a reason: "People don't think of digital assets in the same way as tangible assets."

Yet in an increasingly paperless world, not accounting for passwords and other online records could leave already grieving loved ones or business associates unable to access accounts promptly, keep finances current or continue to run a business.

And unless such provisions are made, some e-mail providers might deny family members access to the deceased's accounts, often a doorway to other online assets.

Take Yahoo's terms of service, found under a link on its home page. At nearly the end of its eight pages, there's a reference to "no right of survivorship and non-transferability."

Digital asset case law is scant, but in one of the earliest court fights over such property, a Michigan court ordered Yahoo to turn over the contents of Justin Ellsworth's account in 2005 after the Marine was killed in action and his family sought to get access to his e-mails.

Several states have passed laws addressing various digital concerns, but the legislation varies greatly. As a result, the Uniform Law Commission has a committee drafting recommendations for state legislatures to enact concerning the rights of a fiduciary to manage and distribute digital assets, copy or delete digital assets and access digital assets.