Tax deduction u/s 80d

One of my friend has paid Rs. 12000/ as premium for medical insurance for self and family in January 2014 and claimed tax deduction u/s 80D. But his office has allowed only Rs. 3000/ for deduction for the financial year 2013-14 because this is the proportionate amount of premium for 3 months of the said financial year as the premium was paid in January 2014.

Kindly clarify whether his office is right in allowing only Rs.3000/ for deduction or it should be total premium paid i.e. Rs. 12000/.