Yes there are several threads on this topic already but I thought if we could put this up on a sticky, that new threads wouldn't come up every few months...
http://www.malaysiaairlines.com/uk/e...n/counter.html
Through check-in for guests holding separate tickets
You can now perform through check-in over the counter if you’re travelling on separate tickets on the following flights operated by Malaysia Airlines (MH) connecting with our Oneworld or codeshare partner carriers, eg EK. With this facility, you’ll enjoy the convenience of having your bags checked through to your final destination when you check in.
Separate ticket check-in requirements for oneworld multi-sector journey
Effective 1 June 2016, [other] Oneworld alliance members are not obligated to offer through check in services for passengers and their baggage to their final destination when they travel on separate tickets on separate bookings. This means that if you have chosen to purchase two or more separate tickets on separate bookings for travel with one or more oneworld carriers, you may have to check yourself and your baggage in again at the end of each sector.
Malaysia Airlines will however, continue to through check-in passengers and baggage to their final destination for travel on one or more oneworld carriers where travel begins with Malaysia Airlines, even if the sectors are ticketed separately on separate bookings. Please note that this may not be possible on your return journey if travel begins with another oneworld member airline that chooses to adhere to the new oneworld obligation.