If I know in advance that there will be editing or proofreading work to do, I can work in the evenings or at weekends to meet a tight deadline.
It is best to contact me before you are ready, whilst you are still writing the text, so that we can agree when I am likely to receive it and how long we have before the deadline.
For longer texts it may be preferable to send through smaller sections as you finish them, rather than waiting until the full text is ready.