Two people who sent millions of spam text messages face being fined more than £250,000, the information watchdog said today.
The messages often claimed to offer payouts for accidents a person has never had or Payment Protection Insurance (PPI) claims that they are not necessarily entitled to, the Information Commissioner's Office (ICO) said.
The pair are accused of illegally sending millions of unsolicited texts and have 28 days to prove they were complying with the law or face fines totalling more than £250,000, the ICO added.
Simon Entwisle, the ICO's director of operations, said: "The public have told us that they are increasingly concerned about the illegal marketing texts and calls.
"These are often made by rogue companies claiming to offer payouts for accidents a person has never had or payment protection insurance (PPI) claims that they are not necessarily entitled to.
"While companies can phone people to sell them the latest product or service, the law states that individuals should not receive unsolicited texts or automated marketing calls unless they have given their permission.
"We know many companies are failing to do this and two individuals responsible for sending millions of illegal marketing messages are now facing six-figure penalties unless they can prove otherwise."
Mr Entwisle added: "We are already working to identify other individuals and companies involved in these unlawful practices."
The ICO has written to both individuals to confirm that it intends to issue the penalties for breaching the Privacy and Electronic Communications Regulations (PECR), which regulate electronic marketing, a spokesman said.
Members of the public have reported almost 30,000 calls or texts received from an unknown sender in the last six months, Mr Entwisle said on the ICO's blog.
"All of this work has led us to where we are today with the ICO poised to issue our first monetary penalty notices," he said.
"This is an important step that shows those who blatantly break the law will be in line for a sizeable six-figure penalty from the ICO.
"We know that many of the companies making illegal marketing calls and sending spam texts try to operate below the radar. However, we have been analysing information from relevant bodies, such as the TPS (Telephone Preference Service), as well as our own complaints figures in order to identify the most complained-about companies.
"We then wrote to companies who featured at the top of these complaint lists to request details of how they were making sure they complied with the law.
"From the responses we received, eight companies are now being investigated further and have been warned that they may face further action unless they can prove that they are compliant."
He added: "While honest mistakes can occasionally be made, we will look to take action against individuals and companies that continue to break the law."