What Does an Under Offer Mean? - Under offer is a term used by estate agents to indicate that a buyer has made an offer on a house. The seller has yet to accept it. Under offer may also be used as a synonym for sold stc, which means that paperwork has not been completed yet. This means that the seller is considering the offer. This is a good way to encourage buyers to make higher offers on a property. It also boosts demand, so be wary of under offers.