There has been new speculation that Vonage violated US Securities and Exchange Commission rules while attempting to reward its customers with a preferred share program.

It could mean Vonage will be forced to buy back preferential shares priced at $17 each, which about 10,000 past and present customers bought. In the highly unlikely event that every single preferred-share owner won back their money, based on the maximum allocation of such stock, Vonage would have to shell out about $78m, if our back-of-the-envelope calculations are correct.

The basis of such conjecture is an SEC filing by Vonage the day before its May 24 initial public offering, in which the company admits to errors that violated SEC rules.

Vonage said an email sent to customers inviting them to be part of its directed-share program, in which customers could buy shares at the $17 list price prior to the float, failed to include a working hyperlink to its prospectus. This hyperlink also was missing from a web page for prospective directed-share buyers.

As a result, it is possible that the email communication and the first page of the website could be determined to be an illegal offer in violation of Section 5 of the Securities Act, in which case recipients could seek to recover damages or seek to require us to repurchase their shares at the IPO price, read Vonage’s SEC filing.

In other words, Vonage may be liable to buy back the shares it sold to customers under its directed share program at the $17 list price. Just how many of those shares it actually sold is unclear, because Vonage has declined to discuss its IPO with the media.

A company spokesperson has cited a mandatory quiet period following its IPO. However, the spokesperson could not answer why, if it is in a quiet period, Vonage issued a press release recently saying it would not repurchase shares of common stock from its customers who didn’t want to pay for them.

The company has, however, agreed to reimburse its underwriters if those customers do indeed renege on the deal.

Of course, some Vonage customers who bought into the directed-share program have been disgruntled with the stock’s performance, and have said the program was anything but a reward.

The stock, since debuting on the New York Stock Exchange at $17, has lost more than 30% of its value. On Friday June 2, it rose 3% from the previous day to close at $11.98.

In its SEC filing, Vonage also admitted it erred with a voice mail message, intended for its directed-share buyers, that did not include the contact details of a point person responsible for making the prospectus available.

As a result, it is possible that the voicemail could be determined to be an illegal offer in violation of Section 5 of the Securities Act, in which case recipients could seek to recover damages or seek to require us to repurchase their shares at the IPO price, read the Vonage filing.

An independently run Vonage-focused chat room, vonage-forum.com, showed messages from posters claiming to have bought directed shares and seeking to back out of the deal.

One poster asked whether anyone had filed a complaint with the SEC, to which there were no responses. Others said they would refuse to pay for the shares. There were no reports of lawsuits against the company as of press time.

In its SEC filing, Vonage deflected the risks of potential legal and financial fall out from its mistakes.

We believe we would have meritorious defenses to any legal actions based on claims of alleged defects in the email, website or voicemail. As a result, we believe that the risks to us relating to any such potential claims are not significant, read Vonage’s filing.

The snafu is reminiscent of Google Inc’s 2004 IPO, in which it potentially violated SEC laws with a preferred share program for employees. The company offered to buy back about $3.1bn worth of shares because it failed to register them.

Of course, Google shareholders were richly rewarded with a steadily rising stock price following its IPO.

While it is unclear whether Vonage will eventually face legal ramifications for its IPO glitches, the possibility of defections from its customer-stockholders seems real.