Can I Use More Than One "Xbox Live 14 day Trial" code?

I recently purchased an Xbox One S, and I a couple games. I have many "14 day free Xbox Live" codes with everything. Can I use all of them? Or am I limited to only one?

Same question but with Game Pass? I used the 14 day trial that was on the Xbox screen, but I have a 1 month pass as well. Can I use that after?

If YES, can I add them all at once to activate when one expires the next takes over? Or do I have to cancel subscription before the charge, and then input a new code?

Yes, you can. I'd recommend buying trials online for around 3 dollars when running out. They give you all the same benefits that normal gold does except the free games per month. It works out much cheaper as well.

Just be careful not to buy the wrong code, as in.. Make sure it comes from the country you live in or it won't be viable.

Use them separately too, just in case. I am not sure if they stack with time.

No, you can not stack 14 days trials.

For example, if you have two 14 day trials, you can't stack them both. You need to use one and after 14 days use the other.

I tried to stack three 14 day trials but they didn't.