Index & match SUM multiple worksheets

Thanks so much for that Pete!

I've inserted the formula as you've instructed and its worked for the EntApr11-EntFeb12 worksheets but I'm missing the last 5 worksheets.

I basically need a total for each staff member across all worksheets

I have now renamed so that it begins with "Ent-"TEXT but it doesn't seem to be adding the rest

Is there another way I can add on to that formula to have the last 5 worksheets added as well?

Thanks,

Thi