A leak at the second stage regulator is who's responsibility, the propane company or the home owner?

Thanks guys.

Depends on whether you own the tank or lease it.
Even with a lease, it could be on the home owner; you would need to see what the contract says.

Tank is leased

Make a call to the propane company and see what they say.

Even if you lease the tank, any leaks are on you after the first year. During the first year you should be able to get any leaks covered under warranty, but any lost propane is yours to cover.

Going from memory. I worked for a large Property and Casualty insurer of propane operations.
I remember the propane company usually owning the regulators thus their issue.
I do know their insurer would demand that they fix it immediately regardless.
Please get it fixed asap. LP leaks of any kind need to be addressed immediately. I've seen claims where a leak allows the LP to follow a line into an enclosed area as LP is heavier than air and will flow almost like water. Fills the area like water in a pool until there is an ignition source.
Again, please address this immediately.

Many of the propane service provides in rural Texas will do a leak down (lines must hold 12 pounds of pressure for 20-30 minutes here in Wise County) test at the point of entry to the home. Not sure who's responsibility within the home but most flex line couplers can be checked with soapy water. A propane leak in the home is an extremely dangerous situation and should not be ignored.

My neck of the woods...exterior=theirs, interior=mine.