Two companies planning to provide electronic postage services Monday won final certification from the U.S. Postal Service and will soon learn whether consumers will be willing to head to the Internet to avoid standing in lines.

Stamps.com Inc., E-Stamp Corp. Monday announced plans for a nationwide rollout of their Internet-based postage services.

News of the approval caused the shares of the only publicly-traded company in the group to rocket on Friday. Stamps.com (STMP) shares rocketed 8-7/16 to 36 on Friday amid reports of the impending announcement.

All the companies allow anyone with a laser or inkjet printer to pay for postage over the Internet and print postage-paid envelopes using their own equipment.

When a user buys electronic postage, the systems will use Postal Service computers to verify addresses. However, since only domestic addresses can be verified, electronic postage cannot be used to send international mail.

Small businesses are expected to be the biggest users of the service. According to International Data Corp., the market will expand to $70 million by the end of the year and could grow to account for 10 percent of all small business postage spending in the next five years.

E-Stamp's complete postage kit costs $49.99, which includes E-Stamp software, documentation and labels. The minimum postage purchase is $4.99 and the maximum will be $24.99. There are no monthly fees charged, however a 10 percent fee is added to all postage purchases.

Stamps.com has different pricing plans for businesses and individuals. Monthly fees range from $3.99 to $19.99 and are in addition to a 10 percent convenience charge.

Neopost and Pitney Bowes are two other companies preparing to offer electronic postage.

Neopost's product, Simply Postage, also retails for $49.95. Users pay a $17.95 monthly fee and $5 for each postage download.

Pitney Bowes is expected to soon rollout its ClickStamp Online product, although no pricing details have been released.