The Financial Conduct Authority (FCA) is seeking examples of occasions the industry suspects it may have applied its rules after the fact with the benefit of hindsight.
It wants to know whether it or its predecessor the Financial Services Authority (FSA) may have applied a more demanding standard or interpretation of its rules after having consulted on, and agreed, them.
The FCA has previously expressed concern about acting retrospectively and said it had work to do to improve certainty for regulated firms.
It recently published the outcomes of its work on a perceived ‘expectations gap' between regulators and industry.
This considered how any differences in understanding might affect the quality of products and services consumers receive, or inhibit consumer-friendly innovation.
It asked the industry whether market development was being held back by uncertainty around rules, or concerns over retrospection.
As a result, it launched Project Innovate, and opened a consultation on guidance on what is, and what is not, a personal recommendation.
It said it "remains interested" to hear from firms about times when they believe it, or the FSA, has applied its rules retrospectively.
Stakeholders should send written examples to the FCA by 10 October 2014 or complete this online form. The FCA requests participants be as specific as they can.