Hello,
Sorry for the later reply!
We are on 7 days holiday, and we are back to work now.
I can promise that you can receive the dress before December if you order it in few days.
Generally speaking it will take about 15-20 days to make the dress, for all of our orders are made to order not in stock. And your event is on December, time is enough for us to make the dress for you.
Any other question, you can comment here or email to our customer service at: service@kissprom.co.uk.
Best wishes
Miranda

Before placing order, talk to them, tell them your time, they will tell you if they can make it for you. I did this before placing my order.