Co-sell­ing refers to the prac­tice of two or more com­pa­nies work­ing togeth­er to sell their prod­ucts or ser­vices to a com­mon cus­tomer base. This can involve a range of activ­i­ties, such as joint sales pre­sen­ta­tions, shared mar­ket­ing efforts, and cross-sell­ing to each oth­er’s customers.