There is a general distinction in Horizon2020 between EU-Member States, Associated Countries (which signed an Association Agreement with the EU) and so called Third Countries (all others which are not EU-Member States or Associated Countries). Third Countries are listed in the Annex A of the Horizon 2020 Work Programmes for every thematic.
In addition, the Annex A states that "legal entities established in countries not listed above and international organisations will be eligible for funding:
- When funding for such participants is provided for under a bilateral scientific and technological agreement or any other arrangement between the Union and an international organisation or a third country."
Here are all countries with bilateral S&T Agreements listed, e.g. the US, Australia, Japan etc.
In order to be eligible for funding in an ITN (or a RISE), a third country beneficiary has to be deemed to contribute with an 'essential participation' in the action. Evaluators will be briefed accordingly. This is considered as absolutely exception. In case an ITN wishes to have a third country beneficiary from one of the countries with an S&T Agreement with the EU, they should ensure a very convincing description of the contribution in the proposal.