There is a specific rule requirement to disclose any possible disadvantages in the suitability report. The rule (COBS 9.4.7) can be seen here: http://fshandbook.info/FS/html/FCA/COBS/9/4.
Remember that a disadvantage is different to a risk. For example, there is a risk that investments can fall in value, whereas a disadvantage would be that the recommended product has higher charges than the product being replaced.



The Transition from Pre-RDR to Post-RDR Unit Classes
Steve Bailey Compliance 2016, FCA, Switch
Changing customers to post-RDR unit classes – important guidance.