WePay updates payments platform, adds ultra-easy invoicing

Online-payments processor WePay has added a new feature to enable its users to quickly and easily create invoices to bill clients. The startup competes against PayPal (s EBAY) and focuses primarily on the small-and medium-sized business market, but touts that its “commerce-in-a-box” platform can help businesses start creating and sending invoices in under a minute.

The new invoicing feature is part of a broader redesign of the WePay site, which allows users to sign up with Facebook Connect and begin sending invoices, receiving payments or charitable donations, and selling items with very little hassle. Invoices in particular are targeted at the SMB market, as WePay hopes to set itself apart from other payment services that aren’t as easy to use.

The invoicing feature is just one part of WePay’s latest update, as the site has also added a host of new premium features. That includes the ability to customize color schemes, add company logos and set up recurring invoices. While there’s no setup or monthly fees associated with the new features, WePay takes a larger percentage of the payment — 6 percent as opposed to the usual 3.5 percent.

While the payments market is heating up through the introduction of startups like Square, as well as innovation being pushed by some of the leaders in the business like PayPal and MasterCard, WePay founder Bill Clerico still sees a huge opportunity as payments move online. The online payments market is about $1 billion trillion today, he told me in an interview, compared to the $20 billion trillion still exchanged by check.

To meet that demand, WePay has raised $9 million, including a $7.5 million round in Summer 2010. It has 35 employees and is based in Palo Alto, Calif.