Until now, Seattle startup Doxo has been pretty secretive about what it’s up to. All it’s revealed is that it’s backed by Jeff Bezos’ Bezos Expeditions and Mohr Davidow Ventures, and that it’s been developing a paperless billing product.

Today, however, co-founder and chief executive Steve Shivers gave me a demo of the service. And the site is now handing out invites and letting in users.

Shivers and his team tried to answer this question: If so many of us are Web-savvy, why haven’t we gone completely paperless? Shivers said 55 percent of US households pay some of their bills online, but only 15 percent of them have gotten rid of paper completely. The gap between the two numbers includes people who still pay some of their bills the old-fashioned way, as well as people who still receive their bills and other messages in the mail, even if they pay online.

There are a couple of problems with the current way of doing things, Shivers said. Customers have to go to separate websites for each bill, and it’s an impossible headache to log in to 15 or 20 different accounts each month.

Doxo should help push users towards a state of complete paperlessness. It offers an online dashboard for managing each account where you need to pay bills. Users will be able to upload their bills (whether they downloaded it from the company website or scan a copy they received in the mail) and store their login name and password for each account. That way, they’ll have all of their billing information in one place. Then, if the billing company decides to create an account with Doxo, they can send you your bills via the Doxo website, and they can send other messages, such as a revised privacy policy.

All of the documents belong to you, Shivers said. Doxo can’t sell the data to anyone else, and you can download each bill whenever you want.

The approach sounds a little like Mint, the popular Intuit-acquired personal finance service. They both bring multiple accounts together and make the data easy to understand. At the same time, by focusing on bills, not financial institutions, Doxo is tackling a different problem. Plus, it has a different business model — instead of making money when it convinces users to sign up for different accounts or credit cards, Doxo will charge businesses, since they’re saving money by not sending paper bills. Businesses supposedly spend $30 billion a year to mail 50 billion bills to customers.

One question right now is whether the service can be useful even if the companies sending you bills haven’t signed up with Doxo. Shivers predicted that the experience will vary from user to user. Some will be fine just using Doxo as a repository for bills and account data. Others will find that a number of the businesses they need to pay are in Doxo already. And yes, there will be a group that doesn’t get much use out of the site right away, but they might sign up for the companies whose bills they want to pay, and then they’ll receive notifications as businesses join.

There are some shortcomings right now — mainly the fact that you can’t make payments on the Doxo site. Doxo just gives you the bill, hands you over to the billing site, then you can mark the bill as paid in Doxo once you’re done. But Shivers said Doxo is definitely looking to add in-site payment features, mobile features, and more.

doxo screenshot