The invention provides seed and plants of the pepper line designated SBY28-1223. The invention thus relates to the plants, seeds and tissue cultures of pepper line SBY28-1223, and to methods for producing a pepper plant produced by crossing a plant of pepper line SBY28-1223 with itself or with another pepper plant, such as a plant of another line. The invention further relates to seeds and plants produced by such crossing. The invention further relates to parts of a plant of pepper line SBY28-1223, including the fruit and gametes of such plants.