Is there a way to deactivate a receiver.

The original owner of the receiver must call in to deactivate it. And, since all equipment is leased, it cannot be transferred to your account regardless. The receiver is automatically a boat anchor.

You should purchase a receiver from Solid Signal, as they can ensure that the receiver they sell can be activated on your account without issue, and all agents there are extremely helpful.

DTV no longer activates deactivated receivers so don't why a CSR told you that.

@Rarline 

You cannot deactivate a receiver from somebody else's account, just like you're not allowed to make any other changes for an account is not yours.

Even if it had been deactivated, DirecTV will not reactivate it. They stopped doing that a few years ago as owned options are long gone. Now when a receiver is deactivated it is returned or recycled if too old a model.

And owned boxes are generally MPEG-2/SD-only so are outdated anyway as DirecTV stopped offering SD-only service in late 2015, meaning none of those boxes could be reactivated a while back even if they were owned. DirecTV has fully adopted their lease-only model with HD equipment.

If you ever find out who's it was, let them know they are still paying for another TV on their account this entire time.

Called back today and asked if they could activate receiver I asked if she could add this receiver to my account. Sure, No problem. After giving her the receiver number and then the card id number took about 5 minutes to have receiver activated and watching DIRECTV. 

Guess the new partners changed the policy.

Well in the short term glad they reactivated it for you. But if it was active on another account then the agent did a big no-no as they had no way to verify you were allowed to have it.

Boxes were not supposed to be transferable between customers except in the very old owned days. At the very least I hope it was an H or HR model so that it will work going forward and not an ancient D or R model.

If it continues to work, then you are very lucky.

Yes. H24

The last HD non-DVR before the SWM-only era. Highly doubt it was 'owned' as those were $399 purchase-to-own before they went to lease-only, though not impossible.

If it remains active, then great. Just be prepared that once deactivated do not expect to get it back on again. You are very fortunate.

The box was likely removed from the previous account upon cancellation, and directv did not want it back from the original owner, who possibly owned the box. If the box you purchased was showing error 726 before activation, this meant that the box was fully detached from any previous account and able to be activated on a new account granted that your account was a pre-AT&T account. 

Are you certain about code 726? The message is asking for the box to be refreshed but this box was never on my account.  Do you think directv will activate it for me? I am pre AT&T.  I have an hr24 that was given to me with that code and would like to activate it to replace a non working HR21 on my account