To have been in membership of a local church which is affiliated with NWBA or BUGB for at least two years
To have the support and commendation of that church - this should originally be sought informally, but will eventually need to be formally granted at a Church Meeting.
A clear sense of calling - this should be more than a desire to train, but a clear sense of conviction from God.
We would normally expect that you can demonstrate a measure of existing ministry responsibility within a local church e.g. preacher, house-group leader, deacon etc.