You've entered too many arguments for this function!

I am trying to build a formula but I am either getting the error message "You've entered too many arguments for this function" or "The specified formula cannot be entered because it uses more levels of nesting than are allowed in the current file format"

The formula I have is:

IFERROR(VLOOKUP(YEAR(C2),MMD!$E$2:$Q$15,IF(MONTH(C2)=1,2, IF(MONTH(C2)=2,3, IF(MONTH(C2)=3,4, IF(MONTH(C2)=4,5, IF(MONTH(C2)=5,6, IF(MONTH(C2)=6,7, IF(MONTH(C2)=7,8, IF(MONTH(C2)=8,9, IF(MONTH(C2)=9,10, IF(MONTH(C2)=11,12,IF(MONTH(C2)=12,13),FALSE),IF(YEAR(C2)>MMD!$A$32,MMD!$B$32,VLOOKUP(YEAR(C2),MMD!$A$3:$B$32,2,FALSE)))

See the attached file for sample data. So basically whatI want to do is in the tab "Excel Formula" under column D "MMD" I want to have the formula that pulls the numbers from the "MMD" tab in the following logic:
- look at the year in Column "C" from the "Excel Formula" tab and if the year is less than the year shown in tab "MMD" cell E15 (in this case 2028) then look at the month in column B from tab "Excel Formula" and if the month is January then take the January number form the corresponding year (from the MMD tab), if February then the February number from the corresponding year and so on and so forth....as an example since the first example is Month 11 year 2026 then the formula in cell D2 should return the number 2.03 which is found under cell P13 in the MMD tab.
- if the year in Column "C" from the "Excel Formula" tab and if the year is greater than the year shown in tab "MMD" cell E15 (in this case 2028) then look at the year in column C and return the corresponding number from column B " Main Rate". So as an example in the tab "Excel Formula" row 4 the year is 2042 and the month is 11 so cell D4 should have the value of 2.88 found under tab "MMD" cell B30.
- and finally if the year in column C is greater than the year in "MMD" tab cell A32 (in this case greater than 2044) then always take the value of cell B32 under "MMD" tab, so in this case for every year above 2044 the value should be 2.90.

My excel will always be set with those two tabs and the calculation will be done for hundreds of rows everyday since data numbers are changing every day.

Please help!

Thank you!

All of those IFs in the middle of the formula will need a corresponding close-bracket, so you should have 11 close-brackets after the final check on the month (incidentally, you are not checking to see if the month is 10), as well as a value if FALSE. However, can't you just use:

MONTH(C2)+1

and not use any IFs?

Hope this helps.

Pete

Thank you for all your help! Amazing! Glenn - it works perfect!