The security writing on the paper is the first hint.
Second, look at the coat of arms.
A real British Coat of Arms looks like this:
Note the horn is cut off the unicorn on the right on the paper in question.
Third, there are two separate places cited as place of birth. Above, it said Coast Provincial Hospital. But in Block 2, it said King George VI hospital (which is in Nairobi, not Mombasa).
Also, there are two separate styles of handwritten "7" -- one in the block 7 (time of birth: 1137), one in the application number.
Look closer, you can see the slight outline of the horn of the unicorn.
My apologies, I had the wrong document. I see no unicorn horn on the one that was handwritten.