How many sets of documents?

[tabita]

I am sponsoring my parents visitor visa, kindly let me know whether my mother and father need to prepare 2 separate sets of documents(does that mean 2 property statements, all the property is in my fathers name) and also do i need to send 2 separate sets of documents to them or just one set for both, thank you and i will appreciate any reply from experienced people.

[immihelp]

If they are going together for appointment, they need only one set.