National Trust membership

I don’t know the answer but if you go to the website, click on membership and scroll down to Contact Us you should be able to get a definitive answer.

Our NT cards have been accepted in Holland.

UK countries are interchangable .

Bump

Best to contact HQ don’t just turn up. People on the gate won’t know.

Bump

Just Google National Trust of Malta to see all the countries in the world where your membership is valid.

The worst that could happen is that she'd have to pay the entry fee

It took about ten seconds to do a Google search for National Trust of Malta and find this page - dinlarthelwa.org/about/reciprocal-membership/

If her card isn’t accepted here, it might be worth her while joining while she is here. It depends on how many NT properties you are going to visit. We went away with friends for four days, they joined NT at the first place we visited and by the end of the trip calculated that it had covered all the admission charges of the holiday.

It will be accepted.

Until Sunday the Daily Mirror/Sunday Mirror are printing a voucher for free entry to National Trust properties, the voucher is valid until June 14.

The OP's friends won't even need a voucher -the National Trust of Malta lists all the places with which they have a reciprocal admittance agreement, and the Uk National Trust is one of them.
- dinlarthelwa.org/about/reciprocal-membership/

Yes is the answer.