At present a Netflix subscription is free for the first month and thereafter costs å£5.99 per month. One has the option to cancel the subscription during the trial period if you are not satisfied with the service.
To obtain a one month free trial from Netflix you need to sign up for their account and have to be a first time user of the service. If you don't wish to continue your membership after one month, make sure to cancel it or else it will continually bill you each month.
Simply go to Netflix and create a new account, your first month is free. They will ask for bank details to verify where you live and because they will charge you the day after your trial runs out. If you don't wish to continue, you must make sure to cancel before the month is over.