If agents were not allowed to erect the "Sold" board until contracts
had been exchanged, the meaning of "Sold" would carry a lot more
weight.

It isn't the estate agents doing this. It is the buyers. When having an
offer accepted and ready to roll, I have always insisted as part of the
offer that the board is changed to "Sold STC" and that no further marketing
is done. I don't want to spend £££s on the survey and booking mortgages to
find someone putting in a higher offer 2 months down the line because they
saw the sign.

Christian.