Singapore forum

Yes, technically that is the rule. It's not always applied though and it really depends on who you get at the airport when you're checking in! (I had that problem last year flying to Singapore -- had to buy a refundable flight on the spot so they'd let me board, refunded it later).

Do you have a flight back to the UK? That should be enough. They just want proof that you're eventually going to leave or go somewhere else.

Your RTW ticket should be good enough. It's usually with one-ways that you get a hassle. As I pointed out to the Air Canada lady who wouldn't let me board my flight to SG without an onward ticket last year (my residency visa was waiting for me in SG on arrival, hence the 1-way flight): "What do you mean I need a flight out of Singapore? You can *walk* to Malaysia. I've done it". If you're super paranoid, maybe doctor up a print-out web itinerary from a budget airline just in case they insist on seeing something?

Train tickets can be booked online through the Malaysian railway website. The price is more than double if you book a ticket originating in Singapore, so the best deal is to book 2 separate tickets for the 1 trip: Sing -- Johor Bahru, then Johor -- KL.

Bus tickets to KL you can buy online (the most expensive), at the Queen St. bus station (expensive), or you can cross into Johor and buy your ticket at the Larkin bus terminal (least expensive). Getting here to the bus station in JB involves a lot of transfers (bus to SG check point, bus across bridge, off at Malaysian immigration, bus to bus station) but it's not busy if you go on a weekday and it saves you about S$20.