Never forget your roots! What follows is an extract from The Forme of Data (1390)

A Short Recet for an Actif Custumer Fonnel Take þe Custumer & first see if he hath paied at þe leeste oon invois; if he neuer paied, cast hym aside. Then enquere if he be cancellid; if so, holde hym not actif, how fair so euer his past was. Next take þe laste invois & loke if it be over-due; if it standeth unpaid beyond þe day, marke hym inactif. If he hath paied oon invois or more, is not cancellid, & his laste invois be in good standing, þanne clepe þe Custumer Actif in þe Fonnel.