Mortgage offer agreed; now buying house for less. What will happen?

[FourForYouGlenCoco]

We offered £212k on a house, was accepted. Were a bit overexcited and did our mortgage application straight away, based on 15% deposit. Mortgage offer all sorted for £180k.
Our house took longer to sell than expected and sellers got a bit aggy and said they'd drop the price of theirs if we'd take the equivalent off ours to try and sell quicker. We've now sold, but are now only paying £206k for the house we're buying.
The problem is that we've had our mortgage offer agreed at £180k, leaving us a deposit of £26k, which is fine, but less than the 15% that was the basis of the original mortgage offer. What will happen? Will they let the original offer stand? Reduce the amount they're offering? Make us do a whole new application? I'm going to ring our solicitors tomorrow to ask about it, but wondered if anyone could shed any light in the meantime!

Don't worry - they don't send you a Big Fat cheque! They pay the vendor the amount agreed. What they offer is usually the maximum they will lend, not the actual sum.

Tell your mortgage company the final price, and then your solicitor that sale is agreed, price etc and leave it up to them.

Surely you have an extra £6k to put down on your deposit, so you'll borrow £6k less? Will that still take you under 15%?

You'll need to keep the LTV the same, and the value will be deemed to be lower so as they agreed a £180k loan when the price was £212k - the max they will lend without you having to re-apply with the reduced price will be £175k so you are still saving money as you will be putting in a deposit of £31k rather than £32k in the original plan.

You will need to inform your lender and they will issue a new offer.

You won't be able to complete if the offer doesn't match the purchase price and borrowing amount.

15% of the new sale price is £31, which is fine, and means we need to borrow £175k. I just ring our mortgage broker and let them know the final amounts, and they'll sort it out? Sorry to sound so clueless! We've never sold before so I'm pretty clueless. They won't make us do a whole new mortgage application though right? (That's our worst-case scenario - time is of the essence!)