121. (1) This section applies where a person (in this section referred to as a “representative”) in purported exercise of an authority to act on behalf of an adult enters into a transaction with a third party.

(2) The validity of the transaction may not be questioned in proceedings, nor may the third party be held liable, merely because—

(a) where the representative and third party are in the State when entering into the transaction,subsection (3) applies, or

(b) where they are in another country at that time,subsection (4) applies.

(3) This subsection applies if—

(a) the law applicable to the authority in one or more respects is, as a result of this Part, the law of a country other than the State, and

(b) the representative is not entitled to exercise the authority in that respect (or those respects) under the law of that other country.

(4) This subsection applies if—

(a) the law applicable to the authority in one or more respects is, as a result of this Chapter, the law of the State, and

(b) the representative is not entitled to exercise the authority in that respect (or those respects) under that law.

(5) This section shall not apply if the third party knew or ought to have known that the applicable law was—

(a) in a case within subsection (3), the law of the other country,

(b) in a case within subsection (4), the law of the State.