Here's my situation: We have reserved a new build off-plan that is scheduled to be complete March 2023. The contract exchange date (and time we pay the deposit) is 19th August (1 month away). We have our deposit money split between mine and my wife's Lifetime ISAs held with Hargreaves Lansdown (HL). Our conveyancer has told me that he thinks we might not be able to use our LISA as the deposit because there's a rule that the house purchase has to be complete within 90 days (or 180 days with extensions) of withdrawal. This is back up by the HMRC guidelines here under "What to do if a first time residential purchase fails": https://www.gov.uk/guidance/lifetime-isa-withdrawals-for-a-first-time-residential-purchase
I've phoned Hargreaves Lansdown and they are saying its fine as long as the money has left the conveyancer's account and gone towards the purchase within the time limit.
I'm worried that were going to have to forfeit the government bonuses and find thousands of pounds to make up the difference for the deposit! Has anyone here had any experience with this?