Yes - you can order the sim card as far in advance as you want. In fact that's probably a good idea as you'd be surprised at how many customers seem to leave it to the last minute and get into all sorts of a panic!
For phone sim cards, we send the sim card to you approximately 10-15 working days prior to the departure date you specify in your order. This is because we're restricted by AT&T as to how far in advance the sim card can be activated before it must be recharged. The USA mobile number is allocated only when the sim card is activated.
If you're not travelling to the USA immediately, and require your USA phone number and/or the USA sim card immediately, just email us at help@usapayasyougosimcard.co.uk after you have submitted your order, and request your phone sim card be sent immediately.
For iPad, Tablet, USB modem or Wi-Fi Hotspot sim cards we'll dispatch it to you on the next business day, and you'll activate it closer to your departure date by following our instructions.