The National Association of College and University Business Officers has issued guidance for colleges on using debit cards for financial aid refunds, a fast-growing practice that has led to criticism of the companies that offer the cards, which can have high fees. The association asks colleges to encourage students to use a full-fledged bank account rather than a preloaded debit card; to offer direct deposit of refunds; to use a competitive bidding process; and to negotiate no-fee or low-fee options for students from the third-party vendors that offer the debit cards. About one-quarter of colleges said in a NACUBO survey that they already use the debit cards, and 33 percent are considering doing so.