Selling to The Government: Preparing a RFP or IFB is our topic on The Core Business Show with Tim Jacquet. RFP or IFB is an Oral or written invitation to prospective suppliers to submit a bid on materials or services. ITB is only a solicitation, and does not qualify as an offer because the party making it does not wish to enter into a binding agreement without further negotiations. Also called request for bids (RFB).