Why do you keep disparaging my statements w/out even bothering to check the TPS rules?
What is on the TPS web site is a non-technical guide to the TPS scheme and the underlying legislation. It is not a definitive statement of the law.
The law is what is stated in the legislation, as interpreted by the European and domestic courts - not the guidance produced for that legislation even if that guidance comes form an official source. You cannot discern the boundaries of what is and isn't permissible based on guidance. If you are familiar with the layout of UK legislation, you will know that there is an explanatory note attached giving the key points of the legislation. Even this explanatory material is not part of the law, so cannot give rise to any legal right or obligation.
You repeatedly make very definite statements about what the law says based on sources that are merely guidance. It is rare for the law itself to be so clear cut - in most cases, a more correct answer is "it depends".
In this case, what the law says can be found in
Regulation 21 of The Privacy and Electronic Communications (EC Directive) Regulations 2003 (SI 2003/2426) ('PECR 2003'). If you read reg. 21(1), you will see that the requirement to screen against the reg. 26 register (the Telephone Preference Scheme register) applies both to the person placing the calls ('A person shall neither use...') and, if they are different, the person on whose behalf the calls are being made ('A person shall ... [not] instigate the use of...').
However, UK legislation is limited in what it can do in relation to extraterritorial acts. A 'person' (which, in this context, can be an incorporated body with legal personality such as a limited company), who is outside the UK and is not British cannot be pursued under PECR 2003.
This means that the non-technical summary you quote is slightly misleading. A UK based company on whose behalf marketing calls are being made from abroad that has a responsibility to ensure that calls are not made to people who have opted out - though the UK company can choose whether to do this filtering themselves or engage someone else to do the filtering on their behalf. There is little UK law can do to a foreign company placing marketing calls from abroad into the UK on behalf of a UK company, as arguably the acts of that foreign company do not come under UK jurisdiction.
In some cases, calls are placed from foreign call centres that are evasive as to the identity of the UK party on whose behalf the calls are made. Of course, if the identity of the party causing the calls to be made is discovered, action can be taken against them.
I do not propose to explore the additional complexity that results from PECR 2003 being the transposition of an EU Directive into national law, except to note that other EU countries will have similar legislation transposing Article 13(3) of
Directive 2002/58/EC. Such an exploration would necessarily involve discussion of direct effect and indirect effect of EU law.
N.B. This is written without checking whether there are relevant amendments to the law and and without researching relevant case law. I'm not trying to produce a legally watertight discussion here, merely to illustrate that making a definite statement based solely on official guidance can be misleading.