14 days free trial payment can't process

You'll want to contact support and speak to billing. http://support.xbox.com/contact-us

Hi,

You don't have any sort of a free trial attached to your account. If you were offered a 30 day trial on the console dashboard you'll need to add a payment method in order to take advantage of it.

If you redeemed a trial code like a 2 day or 14 day trial, or even a 30 day trial code from a redemption card then you wouldn't need any sort of payment details. The 2 day/14 day card doesn't give you gold status but lets you play online for the stated days
(2 or 14 days, depending on what you redeemed), or 30 days (which will give you gold status) if you redeemed it from a gold subscription card.

It's some time ago when I tried Game Pass back then when it was in Insider Testing, but you simply sign up for Game Pass as if you were about to buy a real Game Pass subscription, and the first 14 days will be a free trial, that automatically turns to a
paid subscription.

There is no special code or 14 day offer.

You just buy a regular Game Pass subscription, and only start paying after 14 days. However, you need to provide a valid payment method to get the free trial.

if u buy a xbox console then u will get given a 14 day free trial but xbox dont give away 14 days free trial for xbox live gold

Every console comes with a free month trial for up to 3 gamertags. In order to get the trial you have to create a brand new account on the console and it will offer you the trial during the gold subscription sign up. You do have to add a payment method in
order to get the trial.

Otherwise, some games do include 2-day, 7-day, or 14-day trials.