Let G = (A, B; E) be a balanced bipartite graph with bipartition (A, B) . For a positive integer t and two vertices a e A and b e B , a bi- (t; a, b)-path-system of G is a subgraph S consisting of t internally disjoint (a, b)-paths. Moreover, a bi- (t; a, b)-path-system is called a spanning bi- (t; a, b)- path-system if V(S) spans V(G) . If there is a spanning bi- (t; a, b)-path-system between any a e A and b e B then G is said to be spanning t-laceable. In this paper, we provide a synthesis of sufficient conditions for a bipartite graph to be spanning laceable in terms of extremal number of edges, bipartite independence number, bistability, and biclosure. As a byproduct, a classic result of Moon and Moser (1963) [9] is extended.