A proposal for emoji flags of England, Scotland and Wales has been submitted to the Unicode Consortium in anticipation of the next Unicode Technical Committee meeting in August 2016.
The lack of these three flags is a particular issue at international events, where these three countries are displayed alongside other country flags, which leads to weird situations like this:
Current emoji flags are represented by region codes in Unicode, which are based on the ISO 3166-1 standard.
Under this standard, England, Scotland and Wales are all listed as subdivisions of the United Kingdom.
Resuming work on this technical report would be one way that these flags could be implemented.
As with all existing emojis, individual vendors can choose which flags (or emojis in general) they wish to support2.
This proposal is now available in the Unicode document register, and should be discussed at the next Unicode Technical Committee meeting in August 2016.
If approved, it's possible these flags will be supported alongside Unicode 10.0 in mid-2017.
Microsoft, for example, chooses not to display any emoji flags and instead shows the two letter country codes on Windows and Windows Phone. ↩