Is it enforceable if an LOI says the price 'is subject to due diligence'?

This kind of language is common, and it generally reinforces rather than undermines the usual non-binding nature of price in an LOI for a business purchase and sale. Saying the price is "subject to due diligence" signals that the stated number is provisional, expected to be tested and potentially adjusted once financial, legal, and operational review is complete — it's an accurate description of how these deals normally work, not an unusual or specially enforceable commitment.

What it doesn't do is create an obligation to close at that price, or at any adjusted price, once diligence is finished. If diligence changes the picture, either side is generally free to propose a different number, or to walk away from the non-binding price term entirely, without that itself breaching the LOI — assuming, as always, that doing so doesn't separately breach a genuinely binding provision like exclusivity or confidentiality.

The phrase is useful because it sets accurate expectations, but it shouldn't be mistaken for the clause that actually protects you — that's the language stating price and other commercial terms remain non-binding until a definitive agreement is signed. A Treadstone business lawyer can confirm both are actually present in your specific LOI.