I have received payments from Ath Power through Bill.com for several years and have never had a problem and have never been charged a service fee. My recollection is that in the case of Ath Power, that the first payment was by check and then they sent me an email asking if I wanted to use Direct Deposit instead, and provided a link to provide required bank account information. It was very easy.
Shopping Southeast Pennsylvania, Delaware above the canal, and South Jersey since 2008