Every new year, many financial planners prompt clients to revisit and update their estate plans and wills. In so doing, they should begin teaching clients about a new – but critical – area of estate planning: attending to their digital legacies.

“This is just hitting peoples’ radar and it’s something they really need to look at,” said Newport Beach, Calif.-based estate attorney Cheryl Barrett, who often strategizes with financial planners about legacy issues. “For each one of us the growth in our digital lives is exponential, especially as we move assets to the cloud.”

If people die without leaving power of attorney to an executor or trustee with the names of and passwords for their online accounts – financial, professional and personal – those accounts may become inaccessible. Heirs simply may not know of the existence of each and every online bank and investment account. In some cases, repositories of photos, movies, music or other data that the deceased might have wanted to pass on may end up deleted.

“Yahoo and Facebook have very strong walls you can’t get past,” Barrett said. “They don’t cooperate if you don’t have a password. Sometimes they are a little bit better if you have a death certificate, but not a lot.”

Delia Fernandez, a planner based in Los Alamitos, Calif., recalled what happened after one of her clients was struck by a car and went into a coma for two months.

“His wife didn’t know that he had stock options that were about to expire,” Fernandez said. Even if she had known, she didn’t have a password to the account. “Stock options are a good example of something that employers present to their employees online. You don’t tend to get paperwork.”

Sadly, the client did not wake up in time to exercise the options and the couple suffered a $19,000 loss, the planner said.

“There was no recourse for them,” Fernandez said. “It was a case in which he could have exercised them earlier but had waited until the last minute, like a lot of people do. Financial planners often recommend that clients systematically exercise options on a regular schedule for diversification, so perhaps if he'd had such a plan his wife would have known about it. But how many people share that kind of detail with a spouse? Often the (spouse) with the options is also the one who handles the financial decisions” and leaves the other spouse uninformed about the details.

Fernandez said she is in the early stages of beginning to advise clients about their digital legacies to avoid instances like this.

A new facet of estate planning is developing to address these concerns, Barrett said. She urges her clients to use a “power of attorney for asset management” that includes powers to manage digital accounts.

“If the person you have appointed as executor of your will is not digitally savvy,” she suggested, “you can appoint a special digital executor who will act on your behalf after you are gone to distribute or delete your digital assets according to your wishes.”

Barrett also suggests that clients avail themselves of several online services that allow users to input their user names, passwords and wishes for each of their digital assets. These include LegacyLocker.com, Entrustet.com, or Securesafe.com.

She also recommends they read a book published last year, “Your Digital Afterlife: When Facebook Flickr and Twitter Are Your Estate, What’s Your Legacy?” by Evan Carroll and John Romano For clients who want to take the concept of their digital afterlife further, Barrett said she tells them about online services like Greatgoodbye.com will send emails after you die on your behalf – written by you before you die - along with even photos or videos.

“We have already seen some clients’ families who are using online memorial sites,” Barrett wrote in a recent newsletter to clients. “This is something you can set up to create your life story with words, images and audio and even design your headstone.”

To this end, she suggests the sites, Bcelebrated.com or mywonderfullife.com.

Ann Marsh writes for Financial Planning.