Abstract: A concrete forming system for forming first and second concrete walls which intersect each other perpendicularly. Each concrete wall is formed by spaced apart inner and outer panels which are held together by ties. An elongated outer corner form joins the outer panels at the corner while, similarly, an elongated inner corner form joins the inner panels at their corner intersection. The inner corner form is substantially rectangular in shape. A plurality of vertically spaced elongated corner ties secure the inner and outer corner forms together. These corner ties, furthermore, are dimensioned so that a portion of each corner tie protrudes inwardly from the inner corner form. Each corner tie includes a notch spaced outwardly from its innermost end which forms a fracture line across the corner tie. Thus, after the concrete walls are formed, the corner ties are broken along their fracture line by striking their inwardly protruding end with a hammer.