When should mortgage overpayments start having an effect on maturity date?

In Sept 2011 I started making a modest monthly overpayment of EUR50, so an additional EUR200 in 2011. These payments are listed on the statement as "direct credit".

Despite this, the month and year of maturity has not changed from the maturity month/date in the 2010 statement. I know EUR200 isn't a huge amount, but I thought it might have had a minor impact all the same.

Any ideas why this might be? Thanks.

The final date of the mortgage is set based on the original term, the computer is not going to track any overpayments and adjust that date unless you ask the bank to do so. Usually they can tell you what date it will roughly finish if you continue to pay the extra in.