Does the solicitor not make few extra bobs out of this by investing client's money for 30 days?
Most unlikely. I appreciate that there is the possibility that all solicitors sit down and work out precisely when a transaction will close, obtain stamp duty from the client ( we must be in funds at closing before spending your lenders money - we have an undertaking to stamp and register the transaction) arrange to put that money on fixed term deposit for 30 days and then arrange to draw it down on the precise date it matures - making sure not to be late as penalties would accrue which would then have to be paid by the solicitor. In reality, the stamp duty is paid to the solicitor by the client by Bank Draft payable to Revenue and mostly for convenience the transactions tend to be stamped straight away.
In most practices, it would not make any practical sense to do as suggested.
mf