Getting down to 75% ltv

clueless_but_curious

I'm due to remortgage in December this year.  I am due to be at 80% ltv following my current repayments.  I did an exercise with my broker a few months ago to compare mortgage rates at 80% and 75% and it would appear to be a good investment to use my savings and overpay to get down to 75% ltv at remortgage (my provider allows this free of charge).
Following today's Halifax report that average prices are up 8% year-on-year, I wonder whether getting a new mortgage valuation would help reduce the amount of overpayment I would need to make in order to secure a 75% ltv mortgage.  I believe my property does fit with where there has been increases (Surrey village, semi, big garden, outdoor office, etc)
Does anybody have any thoughts or experiences that might help me decide on the best course of action?

getmore4less

You don't have to do it now, best not to overthink these things

You can hold back some of the overpayments to keep a comfortable level of savings
Then see how much if any  is needed in Dec(or before) when they will do your retention offers 

if short top up the overpayments then

clueless_but_curious

I guess I had mentally already moved on from being retained - I've already presumed the best deals are achieved through brokers (although happy to be proved wrong!)
Will the valuation be refreshed as part of the retention offer?

K_S

@clueless_but_curious Generally speaking, about 3 months or so prior to expiry of your current fixed product, your lender should be able to give you your retention options. Normally, this is based on an automatic indexed revaluation (roughly speaking, they take the last recorded value, add a % uplift based on one of the widely used property price indices). This will give you your "new" LTV. At that point in time, you can assess your options and way forward.

If you wish to dispute this valuation, depending on the lender they may allow you to pay for a surveyor valuation whose valuation will usually override the automatic valuation.

Whether a broker will be able to get you a better retention deal or not, depends on the lender policy. For most mainstream lenders, it's the same but it's sometimes hard to get this information as there is an increasing trend of lenders not publishing product transfer rates.

This is anecdotal and based on a small sample, but all the automatic valuations for PTs (product transfers) I've done recently for clients with fixes expiring now have comfortably exceeded client expectations, probably due to the sharp rise in prices recorded in the published indices. So just hold on to any overpayment until you know what the revalued amount is.

clueless_but_curious

Thanks @K_S that is incredibly helpful and informative.  
Reading between the lines of your third para, I will certainly use a broker, as and when