You can account a transaction that's been placed but not fulfilled. I think when someone orders $15m of goods, you can immediately book $15m accounts receivable (asset) and $15m goods owed (liability) as soon as you have the expectation it will happen. If the transaction falls through, you delete them.

Under GAAP you cannot recognize revenue before the service is delivered or product is shipped. You can accrue revenue that is earned but not yet paid (if you are paid on Net 30, for example), but even if pre-paid you have to book that as deferred revenue, which is a liability (until you ship).

There's no deleting anything in accounting.