In the United Methodist Church, Holy Communion is offered at the "Open Table", meaning that you don't have to be a member to take the sacrament. I include a statement to this effect whenever I begin the liturgy:
In the United Methodist Church, we celebrate an Open Table. That means that you don't have to be a member of this church or any church to partake of Holy Communion. You don't even have to be a Christian. Christ invites to his Table all who seek him.
How is this expressed in your congregation?