For most home buyers, a mortgage pre‑approval letter remains valid for about 60 to 90 days. This timeframe reflects how quickly your financial situation can shift. Lenders rely on accurate, up‑to‑date information about your credit, income, assets, and debt before they can confidently issue a final mortgage approval. Because these details can change from month to month, pre‑approvals naturally come with expiration dates. Understanding how long your pre‑approval lasts, why it expires, and what you can do to keep it active can make your home‑buying journey much smoother.