Ideally, you should receive the loan documents and not just a finance approval letter, before you notify that finance has been approved. While there will be a lot of pressure to “go unconditional”, sometimes there are unexpected things in the loan documents; e.g. a further guarantee or a top up condition. Given your capacity to change these things is usually nil, they can make the finance offer unacceptable. If you have already notified finance approval on the strength of the approval letter, then you’ve got a problem.