The Financial Conduct Authority (FCA) and the Chartered Insurance Institute (CII) have created a re-assessment test for advisers with the level four diploma.
While use of the test is voluntary, the regulator has warned it may force advisers to take it if deemed necessary.
The test has been put together because only a few large firms test their advisers' knowledge on a regular basis, and many advisers have never been retested since they originally passed the test.
The FCA said: "We believe that advisers having a good level of knowledge is the foundation to giving sound financial advice. This is particularly the case with the more technical aspects of financial advice.
"The objective of the re-evaluation is to identify areas of strength and weakness in technical knowledge and its application that underpins suitable financial advice.
"We will encourage firms to use it and we may also use it as a supervisory tool if we think it is appropriate to ask firms to re-test specific advisers."
The test will contain 100 questions across areas of the CII’s R01-5 syllabi, prioritised by the potential for impact on the suitability of advice.
The CII will make the Regulated Retail Investment Adviser Re-Evaluation available from Monday, 1 October and advisers will be able to book a test from Monday, 17 September.
The level four diploma in financial planning became the standard when the Retail Distribution Review came into force at the start of 2013.
Advisers complete a minimum of 35 hours continuous professional development each year with the aim of maintaining their knowledge but there is no obligation for retesting.
Matthew Walne, of Santorini Financial Planning, said: "I am all in favour of keeping up to date. We are all trying to prove we are fit, proper and trustworthy and to do that you need to keep on top of the technical knowledge.
"If you cannot pass a level four exam you shouldn't be doing the job. Everyone should be aiming for level six now as standard."