I may have shot myself in the foot here when I made this purchase, hopefully not. Only getting around to posting a question about it now in the forums despite purchasing this back in December 2019 which was definitely silly on my part.
Back in Dec 2019 Best Buy was offering Motorola e5 play phones at an insanely low price ($40) BUT they were listed as " AT&T Prepaid - Motorola MOTO E5 Play " (with 16GB Memory Prepaid Cell Phone - Black, Model:XT1921-2SKU:6300370 ) ... the thing is, I already have two motorola phones for my kids (motorola Moto g4 play model) that are already on an AT&T prepaid plan.
I called AT&T's customer service department at the time and they seemed to think that they would be able to make the phones work with our current prepaid AT&T plan since we're already fulfilling the requirements (an AT&T prepaid plan). I certainly hope I don't have to do anything silly like sign up for a brand new AT&T prepaid plan despite already having one (although my online research seems to indicate in theory I could do this for 6 months with a prepaid plan then the phone would become unlocked).
This is a long shot but..
That is has anyone else bought a phone that normally would require activation with a prepaid plan... but you already have a prepaid plan with AT&T so you just call customer service after swapping your prepaid AT&T sim card into the new phone and it worked?
Thanks in advance to anyone who reads this and responds 
Vince-BBY
Hi there, Andrepartthree!
Thanks for posting with us here on the Best Buy Support Forums. I'd be happy to offer some assistance here regarding your questions about this phone that you purchased from us a while back!
In this case, as you are looking to use this AT&T Prepaid phone on your existing AT&T Prepaid service, I'm happy to let you know that you should be be able to get this new phone activated on your AT&T Prepaid account without any issues. Simply inserting your existing SIM card into the phone should get the phone activated, but if you have any trouble, I would recommend giving AT&T Prepaid a call so they can help you get it all set up!
Hope this helps!
Sincerely,
 | Vince|Social Media Specialist | Best Buy® Corporate Give Kudos if you like this post or Accept as Solution if it answers your query! | | |
Vince-BBY
Hello again, Andrepartthree!
Thanks for following up with us on here! I'm glad to hear that this all worked out in the end, and you were able to get your new phone activated with AT&T Prepaid!
That being said, I do believe that there may be some confusion in your comment, so I do want to clarify. When you see the "Activate Now" option on BestBuy.com, such as what is shown on the Moto E by Motorola, this option can only be used to activate the phone on post-paid Verizon, AT&T and Sprint accounts. Thus, this option cannot be used to activate the phone on a pre-paid carrier, such as AT&T Prepaid. Additionally, it's important to call out that AT&T Prepaid doesn't charge activation fees at this time, unless you are activating a phone at an AT&T store.
Regarding cutting out an existing SIM card, this wouldn't be advised or recommended, as it can cause damage to the phone itself, unless your existing SIM card did have the pre-perforated cutout around the smaller portion of the SIM card. Regardless, should you ever run into issues activating a phone on AT&T Prepaid, or if you ever find yourself needing a new SIM card, giving AT&T Prepaid a call should help to get you all squared away!
Sincerely,
| Vince|Social Media Specialist | Best Buy® Corporate Give Kudos if you like this post or Accept as Solution if it answers your query! | | |
Update again... the $30 activiation fee never happened and the phone worked flawlessly for over a year before my son upgraded to his newer phone and gave me his old phone.
UNLOCKING this phone however was a different story.. AT&T got it unlocked eventually but it was a total nightmare to the point where I begin to question if it's better to just pay the additional money to only buy unlocked phones and be done with it... technically the unlocked AT&T phone is working now with my t-mobile service but there's AT&T bloatware (pretty sure it's bloatware) on the phone that doesn't give an option to uninstall which really slows the phone down - my old phone was actually faster and that was the older model of the phone ! 
... but given the grief and pain unlocking the phone and transferring t mobile service to it (easily 5 to 6 hours minimum of pain and grief talking to various AT&T and T Mobile reps) , for all that grief and pain I'm going to just stick with the slower yet somehow newer model phone
And yes I know you can root your phones , unwilling to mess with that .. like I said unlocking the phone was a nightmare not going through that again if rooting messes with the unlocking somehow.
Worth pointing out that t mobile customers get mcafee security for tmobile for free from the google play store... if you're engaging in any financial transactions on your phone (buying stuff with paypal or credit card or whatever) I think it's a really good idea to get some sort of security software installled on there ...
" Wanted to give an update mainly in case anyone else has the same question (and also because google search turns up posts like this even if one is not part of the AT&T community forums so maybe it might help someone with a similar question in the future?)...
Just as Liz predicted no problems whatsoever getting the new phone up and running.. rather than just swapping the sim card out (sim cards were different sizes on the old and new phones) I ended up calling AT&T prepaid customer service and they had no problem transferring the phone number to the new phone's sim card and getting the new phone up and running.
I am waiting with baited breath to see if a thirty dollar activation fee shows up on my phone bill since I switched to a new phone but the agent did not mention anything about an activation fee I spoke to on the phone and I certainly wasn't going to bring the topic up !
So if I don't post back here again assume I managed to dodge the activation fee 
Speaking of that activation fee however, in some cases it might make the discount you get for "activate now" phones a bit redundant depending on how much of a discount it is ... for cheaper phones (like the moto g fast or moto e year 2020 model) I notice you can get a $50 discount if you select "activate now" on the best buy website.. BUT that immediately forces you into a situation on BB's website where they add a $30 activation fee (if you're using AT&T anyways) so... $50 discount, $30 activation fee, doesn't really save you that much versus say just giving up the $50 discount, buying the phone unlocked, swapping the sim cards out yourself and hoping this bypasses AT&T's activation fee. On the other hand for the more expensive phones I've seen discounts of hundreds of dollars that might make soaking that $30 activation fee worth it.
(I should point out that in theory I could have removed the pre-perforated part around my bigger sim card to make it smaller such that it could have fit into the new phone but I was reluctant to do this in case the new phone didn't work far as transferring the phone number over and I needed to stick with my old phone... but if you're confident the new phone will work then obviously you could do this hoping to bypass the activation fee).