The clause protects against a decision, not against a change of mind. The event it names is the buyer's inability to obtain the described loan, which ordinarily means a lender considered the application and declined it, or approved it only on terms the contract did not contemplate. A buyer who never applied, who applied after the deadline, or who caused the denial by taking on new debt or changing jobs mid-process is in a materially different position, because the condition was written on the assumption that the buyer would pursue the loan. Most forms say so expressly, requiring the buyer to apply promptly and to cooperate in supplying what the lender asks for. Where the form is silent, the question becomes one of state contract law rather than of the clause.
Regulation Z defines what an application is, and the definition is short enough to check against. For the transactions covered by the Loan Estimate and Closing Disclosure rules, 12 CFR 1026.2(a)(3)(ii) treats an application as the submission of six specific items: the consumer's name, the consumer's income, the identifying number the lender needs in order to pull a credit report, the property address, an estimate of the value of the property, and the mortgage loan amount sought. Those six items are the moment the lender's disclosure clock starts. They are also a usable answer to a buyer wondering whether they have applied yet, and the FAQ below sets out the regulation's own wording.
A preapproval is not the condition being satisfied, and the form says so. Regulation Z requires the Loan Estimate to carry, depending on whether the creditor includes a signature line, either "By signing, you are only confirming that you have received this form. You do not have to accept this loan because you have signed or received this form" or "You do not have to accept this loan because you have received this form or signed a loan application" (12 CFR 1026.37(n)). If receiving the form does not commit the borrower, it certainly does not commit the lender. A preapproval letter sits further back still, and the word on the letter tells a reader very little, which is mortgage preapproval's own subject. The sequence a buyer should hold in mind is that a letter is an opinion, a commitment is a decision usually still carrying conditions, and a closing is the only point at which the money exists.
A denial generates the evidence. Under Regulation B, a creditor must notify an applicant of action taken within 30 days after receiving a completed application, and a notification given when adverse action is taken "shall be in writing and shall contain a statement of the action taken", the creditor's name and address, "a statement of the provisions of section 701(a) of the Act", which is the Equal Credit Opportunity Act's prohibition on discrimination in credit, the administering federal agency, and either the specific reasons or a disclosure of the right to request them (12 CFR 1002.9(a)(1), (a)(2)). That notice is usually what a buyer produces to show the condition was triggered. It is also why the practical advice inside a financing contingency is administrative rather than clever: apply early, keep the file complete, and keep the paper.
The appraisal limb often lives here. A valuation below the contract price reduces the loan a lender will make, which fails a loan condition rather than a condition about the property, so many forms handle a low valuation inside the financing clause rather than in a separate appraisal contingency. Two contracts can therefore use the same phrase and give the buyer different exits. Reading the two clauses together, before the offer goes in, is the only way to know which one you have.