We are selling our leasehold flat and we are ready to exchange any day now after a long and stressful few months of negotiations, enquiries, extra costs etc. We've just heard there are major works coming up and we will be issued with a section 20 at some point. Don't know when, don't know how much it will cost. At what point do I have to tell our buyer? There was nothing in the searches, landlords pack or maanagement pack as the works weren't known about then, it's unexpected. We know we are going to have to pay something or reduce the sale price accordingly. But how can we if we don't have a bill yet? I don't want to delay the sale any further or lose our buyer as it's already been delayed several months and we are packed up and ready to go! What happens if we exchange and the section 20 notice comes soon after?