All EE sim cards are able to be ordered and delivered free of charge, although contracts will require you to pay the first month first. Your sim card will arrive up to 5 days after you ordered it and will be in the form of either a nano, micro or standard sim size, depending on your handset.
This service is offered free as a courtesy to you as a new customer. By making you put in minimum effort to receive, setup and activate your free sim card the hope is that you stay long term.
EE offer sim cards either on contract or on pay as you go packages with differing allowances and prices.