As our events are open to delegates from multiple organisations, we charge UK VAT in accordance with The VAT Act 1994, Schedule 4A, para 9A which states that services relating to admissions (inc delegate fees) to events are supplied in the country in which the event takes place.
The provision of in-person business training at an event held in the UK is also liable to VAT at 20% for delegate fees, irrespective of the establishment of the attendee. In the UK, the B2B VAT rules (exceptions) only apply to an event organised for the exclusive use of a single business customer i.e. a bespoke training event for one organisation.
There is only one exception to the rule, which is that training services provided to foreign governments for their sovereign activities (i.e. not for its business purposes) can be relieved of UK VAT (it becomes ZR) provided that confirmatory evidence from the overseas Government Dept is held. This is outlined in HMRC’s VAT Notice 741A at para  15.5