Tax Free Childcare - newbie queries

Hi all

I've just accepted a job that I'll be starting in January 2019.
I currently get childcare vouchers which will stop when I leave, and for my new job I will set up a Tax Free childcare accounts.

I have a few queries:
* How long does it take to set up an account in order to be able to pay in funds to then pay out to a childcare provider?
* Is it possible for me to set up an account now, and not use it until January, or will that mean my current childcare voucher arrangement will no longer be valid?
* Is it possible to pay more than one registered childcare provider?

Thank you for your help.

PT