Don’t. This is my recommendation. They were a solid domain reseller years ago when they were connected with OpenSRS/Tucows. At some point, they hooked up with eNom instead, possibly for not responding to customer issues. Luckily for JumpDomain, eNom has a similar level of apathy towards customers. I learned of this as I tried to get the last of my domains transferred elsewhere over the last several months.
All was well until I tried to do a couple of “global edits” to my domains using the control panel on JumpDomain in 2006. It was a simple series of changes to enable Spam Catcher protection on all 12 domains. This hides my real email address so that bots can’t go through registration records, harvesting spam targets. The global edit sat for a few days, then weeks, and finally several months had gone by. My registrant address was still sitting out there. I couldn’t cancel the job or restart it. Worse yet, support tickets went completely unanswered. Uh oh. I had read about other domain registrars going under, and it wasn’t always a safe trip for the domains themselves. Time to leave.