Does it matter if two social security cards are from different provinces

The two provinces social security cards are in conflict. One ID card can only buy one social security, in the same area, can not pay two. Social security in different areas, you can pay at the same time, but it does not make sense. If the national network, inventory or retirement, found in two places to pay social security, different periods of cumulative calculation of contribution time and contribution amount, the same period will not be cumulative.