The sessions will be confidential with a very few exceptions. This would usually be if you were going to hurt or abuse yourself or another person, or were likely to do so. Except under the most extraordinary of circumstances, if I have to break confidentiality I will discuss it with you first.
Another key exception to total confidentiality is that of professional supervision. As with all accredited psychologists and psychotherapists (not just those in training) I am required to be in regular professional supervision in which I discuss my practice with another experienced professional. More information on this sort of supervision can be found on the BACP website.
Lastly, I use technology as part of my practice including web-based email (Gmail), Dropbox, and Skype. While I encrypt stored files, files transferred across the internet including Skype calls, cannot be fully secured and so a balance must be struck between convenience and confidentiality. While I do my utmost to provide for their security, I cannot absolutely guarantee the confidentiality of client information within these services.
A separate issue is that of trans people under the Gender Recognition Act 2004. If you are trans (or indeed non-binary, cisgender, or any other gender) I will need to disclose that if it is relevant to the Supervision detailed above. In addition, if you require my recommendation for interventions I will naturally need to disclose your trans status to the professional who will provide those services, and to your GP. Also, as detailed above regarding other matters and IT, your trans status cannot be fully secured due to the use of technology.
Notwithstanding these caveats, I understand the need for all psychotherapy and psychology matters, include those relating to gender and sexuality, to be kept as confidential as possible and will do my utmost to see that they remain so.