What must a foreign buyer do before purchasing a good from a British company?

The most appropriate action a foreign buyer must take before purchasing a good from a British company is to convert their currency. This is primarily due to the fact that transactions between countries typically require one party to use the currency of the other party's country. When a buyer from a different nation wishes to buy goods priced in British pounds, they must convert their local currency into pounds to complete the transaction. This process ensures that the buyer can pay the correct amount and that the seller receives the payment in their desired currency.

While options like donating money or waiting for approval may involve various transactions or regulatory processes, they do not specifically align with the fundamental requirement of completing a purchase from another country. Similarly, while filing an export form may be necessary for the seller to comply with legal requirements, it is not something the foreign buyer needs to do to make their actual purchase. Thus, converting currency is the essential prerequisite for initiating an international transaction.