Won’t work if they ask for a CVV code.
I always keep used-up gift/rebate cards around for this purpose. They’re valid credit cards, complete with CVV numbers, and their expiration dates are usually a very long time in the future (got one the other day that expires in 2020).
A completely empty gift card wouldn’t work if they did a $1 test fee (as edgore notes), but a gift card with just a dollar remaining on it would.
