This is an interesting issue - so I have moved it from another thread.
If you want to make an overpayment on a fixed rate mortgage, ring the lender and check the break fee for breaking out of the fixed rate. In many cases, it will be smaller than you expect or even zero. In most cases where there is a fee, you will recover it quickly in the interest saved.
In this case, Frank was quoted a fee of €3,000 on a €200k mortgage balance with 2 1/2 years to go @4.15%
By overpaying €200k , he would save €20,750 (200k @4.15% for 2 1/2 years), so it would be well worth doing.
1) He could just overpay €20k , and would save €2,075 at a cost of €300.
2) He could break out of the fixed rate completely and go variable. When it's variable, he can pay whatever he wants without penalty.
3) As this was a Bank of Ireland mortgage, he would be facing very high variable rates, so he would have to either fix again, but at a much lower rate or else switch to another lender.
Brendan