Most definitely it's not without risk and I didn't mean to come across as definitive, more trying to think of possible solutions.Hi skrooge
This is probably true and it's a brilliant idea.
But I don't think you can be definitive about it.
10 year money market rates might rise between the time he draws down the mortgage and when he looks for a break fee.
KBC might look at getting it based on when he drew down the initial mortgage.
If he stays with KBC, he should look at it but I think the safer option is to apply for a mortgage now to Avant.
Brendan
The first thing to do would be to clarify how the break free would be calculated under the new mortgage. If they can indeed clawback the 11k it's not worth it. I'd be looking at the T&C's closely rather than what the sales people say.
After that there are of course risks of movements in interest rates but over the short term (I'm presuming KBC will pay back the 11k in a matter of weeks) it may be an acceptable risk.
Finally there is no guarantee Avant will take you at their current rate. However this last bit can at least be partially dealt with in parallel.