Thanks guys,

I've spent the last few hours working on this and I figured it out! My
formula as follows:

=IF($B$3="Male", IF($B$4="Non-Smoker", 'Premium Rate Table'!L4, 'Premium
Rate Table'!L5), IF($B$3="Female", IF($B$4="Non-Smoker",'Premium Rate
Table'!L6,'Premium Rate Table'!L7)))

B3 = Drop down list where you can choose "Male" or "Female"
B4 = Drop down lise where you can choose "Non-Smoker" or "Smoker"
'Premium Rate Table' = Separate Worksheet with the Premium Rate Tables.
L4 = Male Non-Smoker Premium Rate
L5 = Male Smoker Premium Rate
L6 = Female Non-Smoker Premium Rate
L7 = Female Smoker Premium Rate
The L# fields already have a VLOOKUP formula to obtain the correct Premium
Rate when the relevant Age is entered.

Thanks for your responses anyway.

Anthony