Its a 360 day chargeback for a local retailer, 180 days for a sales partner like me.
Eventhough the dealer is on the hook for 12 months, they will word 3rd party contracts for 18 months so its the same as the 18 month contract you sign with DISH Network.
Its less confusion to the customer if they both say 18 months, than if one contract said 12 and the other said 18.
As long as the dealer is not getting charged back, then they are not going to enforce their contract. After the 1 year, there is no way for a dealer to tell if you disconnected unless they look at their residuals which is highly unlikely, and even if they did notice it on that report I doubt they would care.
Now the equipment chargeback is 180 days, everytime you do not pay your bill and the service is shut off for non-pay that chargeback period starts over again until you can keep it 180 consecutive days without being shut down.
If you did not pay your bill ontime and was being shut down every 3 months, technically the equipment chargeback is indefinite till you have satisfied the 180 consecutive day requirement.
But if you paid your bill ontime for 17 consecutive months, then you should be in the clear with the local dealer reguardless what the contract says!