Imagine losing everything in a disaster like Hurricane Harvey, then having to list all of your possessions to file an insurance claim — every plate, holiday decoration and piece of clothing for starters.

Without a home inventory, this would be the toughest memory test you'd ever face, and forgotten items could cost you in the form of a lower insurance payout.

"You can lose thousands of dollars because you didn't include everything," says public insurance adjuster David Moore, COO of Jansen/Adjusters International, who's been taking calls at his Houston office despite the crippling storm. Publi...