The Bar Standard Board's Handbook governs certain categories of international legal services provision. It is important that you familiarise yourself with these before you accept instructions from foreign law firms or lay clients. One important rule is that barristers receiving instructions directly from foreign lay clients must complete the public access training. Foreign lawyers on the other hand are defined as professional clients and can be dealt with in the same way as solicitors (except that they would not be able to provide litigation services in England and Wales unless they had a solicitor associate or partner).
While in general terms international practice can be understood to mean delivering legal services cross-border in any mode, the Bar Standard Board's Handbook rules relating to international practice apply only to certain international legal services delivered by barristers as outlined by the concepts of "foreign work", "foreign client" and "foreign lawyer" (see Part 6 of the Handbook (Definitions).
A barrister undertaking foreign work is also required, as a matter of professional conduct, to comply with the applicable rules of the foreign place in question, subject to the overriding Core Duties described within the Handbook.