Who pays UK Inheritance Tax on foreign property

My step-son is to inherit a Spanish property from his natural father who died recently. The value of the property has been included in the UK estate. The executor has apportioned some of the total inheritance tax due to the Spanish property which they are expecting my step-son to pay. Shouldn't it be the estate that pays not the beneficiary ?

Hi,

Please contact the Inheritance Tax team for advice.

Inheritance Tax: general enquiries

Thank you.