If you're a spreadsheet professional, you know that there are many different ways to use the IF function. It can be difficult to decide which IF formulas are valid or not. In this article, we will look at a few tips for evaluating IF formulas. These tips won't solve every problem you might encounter, but they should help you identify and fix common errors.

A valid IF formula must satisfy the conditional logic rules. In other words, the logical tests must be ordered such that the hardest test is always first, and the easiest tests come last. A nested IF formula that does not meet this requirement is considered invalid.

Another important rule is to not create too many IF functions in a single formula. Having too many IFs can make it very hard to build the formula correctly, and they will also be very difficult to maintain over time. This is not to say that you can't use IFs in a complex formula; it's just that you should be sure to break the formula down into smaller sections if necessary.

For example, if you want to find out which products are selling well in your store, it might be easier to use a VLOOKUP or INDEX and MATCH instead of a nested IF function. If you do use a nested IF function, you should also be careful about the order of the logical tests in the formula.

Finally, when using IF with text values, you should be aware that it is case-sensitive by default. To ensure that IF treats lower- and upper-case letters differently, you must use the EXACT function.