The Anglican Journal has a helpful article on “Open Communion,” also known as “Communion Before Baptism.”
The case for open communion
From The Anglican Journal
Should we invite persons who are not baptized to receive Holy Communion? The church is discussing this question today. Anglicans traditionally have believed that the eucharist is a family meal, reserved for members of the church through baptism. Those who are not baptized are not members of the church; therefore, they cannot participate in the family meal.
This exclusive view of the eucharist has a long history. St. Paul warns against eating and drinking in an “unworthy manner” (I Cor. 11:27), though he seems to leave the decision whether to partake in the meal to each person’s conscience (I Cor. 11:28).
Closed communion is standard practice in some Christian churches, including the Roman Catholic and Orthodox. However, many Anglican churches now practice open communion. There are good reasons, both missional and theological, for doing so.