Two spam texters are in line for fines totalling more than £250,000, in the first exercising of powers given to the UK's Information Commissioner's Office last year.
The as-yet-unnamed individuals will have to pay the fines unless they prove during the next four weeks that their actions were legal, the ICO said on Monday.
"It would be the first time we've issued a financial penalty for breaches of electronic marketing regulations," a spokesman for the data protection watchdog told ZDNet.
In a statement, ICO operations chief Simon Entwistle said the public was "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 PPI claims that they are not necessarily entitled to," he added. "The law states that individuals should not receive unsolicited texts or automated marketing calls unless they have given their permission."
The ICO gained enforcement powers around the Privacy and Electronic Communications Regulations (PECR) in 2011. It is able to issue fines of up to £500k for offences under these regulations.
According to the spokesman, the two individuals involved in this case were both linked to the same company, but "the way the company is structured leaves the individuals responsible".