Hi,

I hold an US L1 visa. Recently my spouse applied for L2 and it so happens that validity for which L2 has been issues is 5 years, whereas my L1 is only valid for 3 years. Is this normal or has there been an error on the part of consular office.
Do I need to re-submit the L2 and get it corrected?

Most L-1 renew their contracts for one more term, so in this case, spouse does not need to renew visa again, which is good for you. It's not clerical error.