PrimeVideo.com/MyTV

Open the Prime Video app on the television and choose Sign in and Start Watching, or Register on the Amazon Website. The TV then displays a registration code. On a phone or computer, go to primevideo.com/mytv, sign in to the Amazon account that holds your Prime membership, enter the code and confirm. Confirming the code registers the television to that account, and the app leaves the code screen. Steps 1 to 5 above walk through the same sequence.

MyTV is not a menu inside the Prime Video app; it is a web address. Amazon's help page on installing Prime Video calls it the Register a Device page and gives it as primevideo.com/mytv. You open it in a browser on a phone or computer rather than on the television, and it asks only for the code the TV is showing plus an Amazon sign-in.

You need a paid entitlement on the Amazon account you register with. Amazon's Prime Video Usage Rules cover both in one section on Prime and Prime Video subscriptions, and say videos available through a paid Prime or Prime Video subscription or promotional trial can be streamed — so either one works. Registering a device at primevideo.com/mytv links the television to an account; it does not create a subscription, so without one the titles will still show a purchase or rental price.

They are two names for one service. Amazon Prime is the wider membership that bundles that service with other benefits. The registration flow does not change either way: the television shows a code, you enter it at primevideo.com/mytv, and the device is attached to the Amazon account. Which entitlement the account carries decides what plays afterwards, not how the device registers.

Installing and registering are two separate jobs. Amazon's help page says to open the app store on your device, search for Prime Video, download and install the app, then open it. Only at that point does the app draw a registration code and send you to primevideo.com/mytv. If the device's store has no Prime Video app at all, no code will ever appear.

Work through account, network, then registration, in that order. Prime Video's login-issues page says to make sure you are using the details of the account you actually want to use, and to try again because temporary connection problems cause some sign-in failures. If the app opens but nothing plays, the television may still be registered to another account: deregister it under Account & Settings > Devices and register again.

Casting is a different path from registering, and it needs no code. When you cast from the Prime Video mobile app, the phone stays signed in and the television only receives the picture, so primevideo.com/mytv is not involved. Register the device instead when you want the TV to keep your profile after the phone is put away — that is what the five steps above set up.

Removing a television means deregistering it, not deleting the app. Prime Video's page on sign-in and sign-out problems gives the route for when you cannot sign out on the device itself: browse to Account & Settings > Devices on the Prime Video website, then click Deregister next to the device you want to remove. The app can stay installed: without a registration it simply shows the code screen again the next time someone opens it.

Amazon's Prime Video Usage Rules set the limit per account rather than per device. A Prime or Prime Video subscription can stream up to three titles at the same time, and the same title on no more than two devices at once; a rented video plays on only one device at a time. Amazon adds that the number of devices you can stream to may vary from region to region. Registering more televisions does not raise those numbers.

Downloads are made inside the Prime Video app on a phone or tablet, not through primevideo.com/mytv, and Amazon's usage rules cap them. With a Prime or Prime Video subscription you can hold downloads on two devices at one time. A purchased video may be downloaded to four compatible devices, and a rented video to one.