The European Communities (Amendment) Act 1986 (c. 58) is an Act of the Parliament of the United Kingdom which saw the first major amendment to the European Communities Act 1972 since the UK first joined the European Communities thirteen years earlier to include the provisions that was agreed in the Single European Act which was signed on 17 and 28 February 1986 and be incorporated into the domestic law of the United Kingdom It was given Royal assent on 7 November 1986.