How does it actually work this exchanging contract lark?

[tracyk]

If our buyers' buyers are going into their solicitors office to sign today. Do all the solicitors then have to post all the contracts to each other before its final - or do they just let each other know by phone that everything has been signed?

yes the exchange is done electronically or by phone. It doesn't just depend on the contract being signed though - ours were signed for weeks before exchange! The solicitors basically do checks to make sure that all the relevant paperwork is in place and that everyone has agreed to the completion date.

Hope yours goes well!