Companies making nuisance calls have been warned to expect total fines of more than £1m next year.
Around 170,000 people complained to the Information Commissioner's Office (ICO) about nuisance calls and texts this year.
The figure was a slight decrease on 2014, when 175,330 people contacted the ICO to raise concerns.
Payment protection insurance (PPI) claims prompted the most complaints, followed by accident claims, the watchdog said.
Call-blocking services, oven cleaning and industrial hearing injury claims were identified as emerging sectors for nuisance calls and texts.
The ICO imposed penalties of more than £1m in 2015, with the same amount in the pipeline.
Andy Currey, enforcement group manager for the ICO, said: "Nuisance marketing calls frustrate people.
"The law is clear around what is allowed, and we've been clear that we will fine companies who don't follow the law.
"That will continue in 2016. We've got 90 ongoing investigations, and a million pounds worth of fines in the pipeline."
These fines include £295,000 for companies offering call-blocking or nuisance call prevention.
Among the punishments handed out by the ICO this year was £80,000 for a PPI claims company that sent 1.3 million text messages. A solar panels firm that made six million nuisance calls was fined £200,000. The ICO also hit pharmacy company Pharmacy 2U Ltd with a £130,000 penalty for selling customer details to marketing companies.
And Help Direct UK Ltd, Oxygen Ltd and UKMS Money Solutions Ltd were fined £400,000 for nuisance text messages.