Will my data plan get erased if I reset my iPhone 6s My data plan is with T-Mobile and I have to reset my iPhone 6s but I'm worried my data plan with T-Mobile will also get erased.

So, has resetting an iPhone any impact on a data plan?
Resetting your iPhone will not impact the contract (data plan) you have with a carrier. You will loose all data stored on the phone itself though, so make sure you have a backup (or, if you store your data in the cloud, the login/password data for all your online accounts).