The UK/Italy Convention for the Avoidance of Double Taxation of Income (or Double Tax Treaty) was signed at Pallanza on 21 October 1988. 
It entered into force on 31 December 1990. It came into effect in the United Kingdom from 1 January 1991 for petroleum revenue tax, from 1 April 1991 for corporation tax and from 6 April 1991 for income tax and capital gains tax
It was ratified in Italy by Law no. 329 of 5 November 1990 and came into effect generally in Italy from 1 January 1991.
The Italian version is here
The text of the treaty is based on the model treaty published by the OECD in effect at the time of signature. Worthy of the note are the provisions extending the tax credit on dividends paid by companies resident in one signatory state to recipients resident in the other. Due to intervening reduction of the tax credit under both country’s domestic legislation in the meantime, these provisions are now redundant.
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