My employer tells me that they will match 25% of my contributions up to 8%. I guess that means 8% of my gross salary is eligible for a 25% match.

I'm starting contributions from Oct 1 and they have a 15% cap. They are saying they want to cap my contributions at 15% of my paychecks, which will mean I'll contribute far less this year in total than 8% of my annual salary.

Am I allowed to say, hey, I really want to contribute more than 15% in Q4 to get closer to 8% of the total allowed for the maximum match.

Am I also allowed to say, hey I really want to contribute more than 15% in Q4 to get closer to the $17.5k max allowed by the IRS?

Edit added: I have been with this company for more than a year, I have only become eligible for 401k in Q4 2014 (hire date was sep 2013, became eligible after 1st anniversary).