Formula to Validate Invoiced Rates Against a Rate Card

Hi,

We have agreed maximum rates with suppliers for certain services and I'd like to check that the rates they have invoiced fall below the agreed maximum.

I've attached an example of the data I'm working with. What I'm after is a formula that will cross check the details and rate charged on the 'Invoiced' tab against the three 'rate card' tabs and generate an output that flags any discrepancies. I've added a column called 'Validate' on the 'Invoiced' tab where I'd like this formula to go.

All the data should match with the exception of the shift which is listed as a description on the rate card but is a concatenation of the job role and an abbreviation of the shift (D = Days, N = Nights/ Saturday and O = Sunday/ Bank Hols).

If you have any queries just give me a shout.

Thanks in advance,

Snook