I have encountered the phrase "due diligence" in the business world. The usage examples I have seen (mostly emails) cannot exactly be considered grammatical canon. An internet search produces lackluster results. Most usage examples refer to the "due diligence process". But in my business it's not a formal process, but an ambiguous obligation.

The usage I am familiar with is similar to the following:

We need to do our due diligence to investigate this.
We need to use due diligence to investigate this.
We need to perform due diligence to investigate this.

Is any of that correct?

7 Answers 7


A lawyer referring to the process of investigating a potential merger/investment might say:

We need to perform due diligence.

There is also business buzzword of "due diligence", derived from the legal meaning to mean the level of care/attention that one would reasonably be expected to take in this situation. In my (American) experience, this is commonly used in the business world as an idiom:

We need to do our due diligence.

One can also consider the literal meaning of the words. "Due + Diligence" = "Appropriate Attention", so one could say:

We need to give this investigation its due diligence.

Looking at the OP's original three phrases according to this guidance:

We need to do our due diligence to investigate this. (correct, business usage)

We need to use due diligence to investigate this. (incorrect)

We need to perform due diligence to investigate this. (most likely incorrect, unless you're dealing with a business merger)

  • It is true, this is just a business buzzword for me. And now I've done my due diligence to learn how to use this phrase.
    – Stainsor
    Mar 26, 2012 at 16:14

"Due diligence" is a legal term to describe when one has exercised an appropriate level of caution or investigation prior to acting or making a decision. To "do due diligence" is an attempt to use the legal term in a grammatically inappropriate way.

A more appropriate ways to express oneself, if one really must force the legal term into one's sentence, would be to "exercise due diligence." Personally, I would prefer if people could merely express themselves intelligently while conveying the same message without forcing the legal term such as to "be duly diligent."


I think due diligence is an overused term. (Gets my ol' pet-peeve-o-meter going.) It is not a synonym for doing your homework. As FumbleFingers says, the people who do it for a living know what it is. Everyone else should use a different term. For example, you could say:

We need to investigate this thoroughly.

We need to do our homework on this problem.

Anything but "do due diligence."

  • I agree- it shouldn't be a synonym for those things, but that's exactly what it has become, and I suspect it has become so prevalent that it would be impossible to stamp it out now.
    – Jim
    Mar 10, 2012 at 0:07
  • 2
    For better or worse, perhaps it's evolving into a generic metaphor - but doesn't that happen a lot? After all, auto mechanics don't mind when people say they'll "take a look under the hood;" Chef Ramsey doesn't throw tantrums if he hears someone talk about plans to put something "on the back burner;" pilots don't get miffed if a college student says it's time to "bail out" of school. If "do our homework" can be used metaphorically, couldn't "due diligence" work as a metaphor as well? (Don't get me wrong - not a challenge to what you said - merely thinking out loud...)
    – J.R.
    Mar 10, 2012 at 4:56
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    @J.R. I think there's value in both sides of the argument. Language is constantly shifting, no one can stop that and it's not necessarily bad, but much of the shifting seems to come from people just using terms inappropriately, perhaps out of ignorance. This seems like a really wasteful process (and kind of lazy) since more appropriate language already exists. It seems to happen a lot with business-speak when someone wants to sound like they know what they are talking about when they don't. My absolute most hated example of this is "going forward". Whatever happened to "in the future"?
    – Mike G
    Mar 10, 2012 at 7:20

None of OP's constructions seem good to me. They all seem to imply that the investigation would not be possible without due dilligence, but clearly a sloppy investigation could in fact be performed, even if this wasn't desirable. I would expect something like:

  • We need to exercise due diligence in investigating this.


  • We need to investigate this with due diligence.

There's also the specialised commercial/legal usage in which one performs due dilligence, but that's probably nothing to do with what OP is thinking of. It's a clearly-defined process involving checking all the details of an organisations assets, liabilities, etc., as part of a coporate takeover.

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    But I suspect that the OP's usage was borrowed from the legal usage. And that his usage implies that a detailed check of all (assumed well-understood set) pertinent information be performed prior to making a decision.
    – Jim
    Mar 9, 2012 at 22:47
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    @Jim: Not sure what you mean by "borrowed from the legal usage". The guys who actually perform due dilligence know exactly what it means, and what they have to do. You don't just randomly apply that kind of "due dilligence" to any old problem you happen to be investigating. And most managers would blow a fuse if they thought any of their staff were trying to introduce those formal concepts into normal operations. It's the last thing the buying company does before signing the cheque. No-one even starts it until everything else has been done, because it's so burdensome. Mar 9, 2012 at 22:55
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    What I meant was some manager somewhere heard the guys from legal talking about "due diligence" and said hey I can bend that term to my own use when I ask my engineers to evaluate whether option A or option B is better-
    – Jim
    Mar 10, 2012 at 0:02
  • @Jim: Hmm. I know it's not uncommon to hear the boss say something like "We need to hold a post-mortem on why our server crashed three times yesterday", but this one sounds more akin to saying "We need to hold a full public inquiry...". Maybe there are people who talk like that, but I doubt they have much credibility, or rise far up the ranks, in a professional corporate environment. Mar 10, 2012 at 0:17

Loosely rephrased, "due diligence" means something like "necessary attention". Strictly speaking, "due diligence" should be used to mean the attention and effort necessary to complete the task correctly. For instance, if you drive with your eyes closed, you are driving without due diligence. Of course, with the way language evolves, this usage has become rare.

Colloquially speaking, it is used to mean the recommended research in advance of a decision - e.g. if you bought a house without checking to see if it was structurally sound, and the house then collapsed, a person might (and certainly a lawyer would) say you failed to do your due diligence before buying it. Checking the build quality is an advisable action to take before buying a house, and therefore many people would consider it a part of the house-buying due diligence. Some might not.

At any rate, it is now, in the business world especially, little more then a buzzword. To do your due diligence is now usually used simply to mean checking off every activity you need to complete before making a decision, so that you are not legally liable if your choice comes back to bite you. e.g. consulting the marketing and legal department before changing your brand name.

To summarize: "due diligence" = "ass covering"


What many people mean in these cases is to exercise diligence or simply be diligent. This has over the years been confused with due diligence, which is something quite specific (as mentioned in other answers).


The phrase "due diligence" appears to imply that a certain level of diligence is "due" from the party "doing" the diligence to a second party. Whenever I encounter this term, it make me cringe, because the people using it [I review commercial appraisals] seem to be unable to speak of diligence without attaching a "due" in front. I think this has more to do with bad habits than it has with intentional meaning. What else could it mean, if it has any meaning at all?

I have tried to discuss this construction with the people use it. They are unable to offer an explanation. Apparently, they think make them sound smart. The effect on me is the opposite.

Remember when the word "impact" (used as a verb) became a common substitute for numerous more precise verbs [affect, influence, help, hurt, teach, degrade, hit, impinge? The list is endless. With "due diligence" we have a similar degradation of the actual meaning of words.

Fie on those who say "Well, our language is evolving, so get over it." Words have meaning. Outside its original use [I looked it up. See Wikipedia.] the term "due diligence" means "I want you to think I am smart". Don't be fooled. It is drivel.

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