Total Sheet to always add up certain persons expenses

Hi,

I am sure that this has already been covered in another thread but after several hours of searching I can't find it so sorry.
I have a spreadsheet with 13 sheets, Month 1, Month 2, Month 3 etc and a Totals sheet called Month 13. On these sheets I have a list of names in column A and various figures in columns B:Z.

What I need is a formula or a macro that will add up the total amount of a certain persons totals from sheets month 1 to month 12. However over the year we will have new people added to the list and so the total sheet needs to be robust enough to change to include those. The way I think of it is:

IF Month13!A3 = Month12!A3 then sum Month1!B3:Month12!B3
IF Month13!A3 ≠ Month12!A3 then find Month13!A3 in Month12!A:A and return sum Month1!Bn:Month12!Bn

The formula I have now is: =SUM('Month 1'!B3,'Month 2'!B3,'Month 3'!B3,'Month 4'!B3,'Month 5'!B3,'Month 6'!B3,'Month 7'!B3,'Month 8'!B3,'Month 9'!B3,'Month 10'!B3,'Month 11'!B3,'Month 12'!B3) But obviously this does not update as names are added. I have a VLOOKUP in place to update the list of names on the totals sheet but when a new name is added then the row numbers get changed in the totals sheet formula and that means my total for that person is incorrect.

I'm sure there is a really simple way to do this and I just can't see it. Any help would be greatly appreciated!

Thank you!

Hi Wombie2903

Check the atached file. The macro will update your list in Month 13 with any new name you add in whatever month. All you have to do is copy the SUM formulas into the new row.

Cheers,
Eduard