Numbers starting +882- and +883- are NOT from Taiwan. These are non-country-specific codes. See https://en.wikipedia.org/wiki/Intern..._(country_code)
Note however that the prices to call these numbers can be very high - for example in the British Telecom price list rates for various 882 and 883 numbers ranged from £0.60 to £4.50 per minute.

The phone service I use to receive calls from UK friends and family at no cost reports my outgoing number as +883 51000xxxxxxx. It's a great service and definitely not a rip off (I pay <£10/year!) - so they just vary. You can see what they offer and/or sign up at http://www.localphone.com