Have I messed up?
I am travelling on a British passport. From Singapore to Hainan and then a week later flying from Hainan to Miri (Malaysia ) however the plane transits through Singapore (1 1/2hrs between flights) is this allowed?
For a British passport holder traveling from Singapore to Hainan, and then onward to Miri (Malaysia) with a transit through Singapore for 1½ hours, here’s what you need to know regarding the 240-hour (10-day) China transit visa-free policy:
The 240-hour transit visa exemption is only applicable if you are transiting through certain Chinese cities (like Beijing, Shanghai, Guangzhou, Chengdu, etc.) and are continuing to a third country within 10 days. Since you are entering Hainan directly, this is not part of the 240-hour policy. Hainan has its own visa-free policies for certain nationalities, including British passport holders, but these are separate from the 240-hour rule.
Regarding your Singapore transit:
For Hainan entry:
Practical advice:
In summary, you have not “messed up.” Your transit through Singapore is permissible, and your entry into Hainan should be covered under Hainan’s independent visa-free policy for British citizens. The 240-hour transit visa does not apply in this scenario, but that is not a problem for your trip.