From "Unlocked" to "Locked"?

[McRumour]

In order to resolve a "Call Forwarding" glitch on my 5S - Apple has suggested I try swapping the T-Mobile nano-sim card (now activated) which came with the phone - for a new T-Mobile card which I'd get at local T-Mobile store.
My phone was purchased thru the Apple Online Store, contract-free. It arrived with the T-Mobile card pre-installed.

Might this swap cause my "unlocked" phone to become a "locked" device?
ie: What's the connection (if any) between a t-Mobile nano sim supplied with an iPhone purchased directly thru Apple - and a card obtained at a T-Mobile store?

 

[Belmont31R]

I am using a nano sim I got in a T-Mobile store and it works fine in my unlocked 5S.

 

[imaginex20]

Wow....

Do you know what the purpose of an unlocked phone is? The ability to swap sims from different carriers. So, why do you think swapping sims with the same T-Mobile carrier suddenly lock your phone?

Just think about it....

 

[McRumour]

I have no doubt it will work.
My question is: Will my phone continue to be "unlocked" as it is now?
I've read on this forum that the new phones purchased at T-Mobile (as opposed to those bought at Apple store) are locked for at least a 40 day period.
I need to know whether swapping sims will cause my unlocked phone to become locked (at least for 40 days)

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Wow....

Do you know what the purpose of an unlocked phone is? The ability to swap sims from different carriers. So, why do you think swapping sims with the same T-Mobile carrier suddenly lock your phone?Just think about it....

I'm seeking guidance. I make no pretense at being knowledgeable......
If my query seems unbelievably stupid.....hey.....this is an area in which I'm totally uninformed - so please cut me some slack.....I come to this great forum for answers to my "dumb" questions

 

[CEmajr]

Your phone can't magically go from unlocked to locked. It's always unlocked so swapping SIM cards doesn't change anything.

 

[McRumour]

ok.....thanks for that reassurance
I have zero understanding of exactly what info is contained on a sim card and whether what it contains has any relation to what makes a phone locked or unlocked.
I don't want to "jump from frying pan into fire" ( solve one problem whilst causing another )
Again...thanks for the clarification.....

 

[Coleman2010]

In order to resolve a "Call Forwarding" glitch on my 5S - Apple has suggested I try swapping the T-Mobile nano-sim card (now activated) which came with the phone - for a new T-Mobile card which I'd get at local T-Mobile store.
My phone was purchased thru the Apple Online Store, contract-free. It arrived with the T-Mobile card pre-installed.

Might this swap cause my "unlocked" phone to become a "locked" device?
ie: What's the connection (if any) between a t-Mobile nano sim supplied with an iPhone purchased directly thru Apple - and a card obtained at a T-Mobile store?

Nothing. It will not "lock your phone." Your iPhone is unlocked and you can use it with any GSM SIM card.

 

[vmaniqui]

reason why T-Mobile iPhone 5S are unlocked is because you're paying full price. compare to ATT which is subsidized. so they have to wait 2 years for the life of the contract before ATT will unlock it (correct me if i am wrong pls.)