How should US owners respond effectively to rental enquiries from the UK and other countries?

Currency is an obvious one. If you are going to quote a rate in US dollars, it would be helpful to quote an approximate equivalent in UK sterling (or Euros, or whatever) too. You will probably require the renter to pay in dollars, since US banks cannot cope easily with foreign currency, but at least give the enquirer a number he can work with when he is comparing your rates with other offers he may receive. It does not have to be too precise, just a ball-park figure will to the job.

Next, state up front how you will need payment. If the renter knows that he is going to have to send you an international money order, then at least he can anticipate what will be involved. If you can accept credit cards, then wonderful. The world has suddenly become a much smaller place! Do not be afraid to ask for an additional charge for taking a credit card payment. Credit card payment is such an attractive option for online transactions, especially with the bonus that cardholders are usually protected against fraud or misrepresentation, that most people will readily pay a little extra.

Make your terms of business appropriate to overseas transactions and postal delays. There is no point in telling a renter in the UK that he will lose his booking if he does not pay a deposit within three days if it will take him at least two days to get a money order prepared and another week or more for it to get to you in the mail.

Finally, be open in your communication with a potential renter from overseas. Try even harder than usual to personalize your emails, so that the renter is aware that he is dealing with a real, credible person. Ideally, indicate that you take bookings from overseas all the time, and that the whole process is really very simple.