I am trying to work out the dividend calculation for the MELCA dividend received yesterday.

Dividend per share = 4.19c
Imputation Credit = 1.66c (25.93%)
Tax @33% = -1.87
Net Dividend = 3.79c

My question is where does the 25.93% come from for the imputation credit? States in the interim report that this is 90% of the corporation tax rate.

And why is not imputation not 100% of corporation tax?