Hi. Thanks for the reply. The mortgage life ends on 2045 and we had 135000 left end of august. At the time we had 100000 in the offset account. So now we have 133000 in offset and 131000 left in mortgageTarget added an extra zero there I think. Just looking at your figures. 21 years left I suspect your mortgage is large enough n even without the extra 30k you already had a good chunk offset and will have maxed out with the doubling.
Remaining mortgage (on 31st August) x term remaining (at 31st August) at 4% interest is the max your pay out can be.