First, read the section of the Standards of Practice on Competence. This includes a standard on adding new areas of practice. Ultimately, this is a self-managed endeavour that can be more or less robust depending on how the individual psychologist engages in it. The Standards of Practice suggest the need for things like consultation with experts, training, education, and supervision.
If you want to provide a new professional service to clients, you must ensure that you have the competence to do so. To determine this, consider consulting widely enough to have meaningfully sufficient information about what competence in a certain area of practice requires. Then, undertake sufficient education, training, and supervision to ensure you are practicing competently. You should document your efforts and the steps you have taken.
There will not be a single nor simple answer to what it takes to build competence in a certain area of practice, but wide consultation with wise experts, meaningful reflection and self-assessment, and legitimate environmental benchmarking can certainly help. It is useful to consider competence in retrospect, as well. Imagine needing to justify working in an area that was never a part of your initial Supervision Plan. What would a group of your reasonable and well-informed peers expect from you to justify your work in that area and how would you support your claim at competence?
Your yearly practice permit renewal includes a section where you declare the kind of work you do. Everything you do should be represented there. If you want to include specific activities undertaken to add new areas of competence, you may record this in your Continuing Competence Program. However, this is not a requirement. CAP does not require you to notify us about new areas of practice, specifically. We encourage you to keep your own records.