A right of audience is a reserved legal activity for the purposes of the Legal Services Act 2007, and a barrister is authorised by the Bar Standards Board to carry on that activity.
During the transitional period, every barrister is deemed to be authorised by the Bar Standards Board to exercise a right of audience in accordance with the Board's regulatory arrangements, provided he has a current practising certificate.
So anyone claiming to be a Barrister should be asked if they have a current practising certificate if they approach you in the waiting room.
The Bar Council has issued guidance on the matter (revised in January 2017) which can be found here. There is also a copy you can download in the link at the bottom of the page. It clearly says there are doubts on unregistered and those without practicing certificates appearing as Solicitor's Agents.
This guidance should now be read in conjunction with the decision of District Judge Peake in McShane v. Lincoln in the Birkenhead County Court on 27 July 2016. On the evidence before him, he held that a solicitor’s agent did not have a right of audience to conduct a Stage 3 Hearing to assess damages pursuant to the Pre-Action Protocol for Low Value Personal Injury Claims in Road Traffic Accidents. This decision of an experienced district judge, who had heard full argument on the issue, is likely to be persuasive in other similar cases. Indeed, its reasoning has been reflected in a subsequent decision of Deputy District Judge Hampson in Ellis v. Larson in the Manchester County Court. He also held that a solicitor’s agent had no rights of audience in relation to a Stage 3 Hearing, for very similar reasons.
If you are going to a hearing, take a copy of the guidance with you together with copies of McShane v. Lincoln and Ellis v. Larson. At the beginning of the hearing, raise the issue and offer the three copies to the judge for his view on the matter. You have the right to a fair hearing.