Being locked doesn't trap that credit in points. You locked to a day's rate sheet, never to one rigid rate. From that same sheet you can move down to a lower rate by paying points or take a higher rate in exchange for a lender credit. Whether the builder's credit can become a 2-1 buydown instead comes down to the specific investor your loan is locked with and whether that investor's guidelines allow the 2-1 structure on your loan. - If they allow it, you should be able to switch the allocation. - If the lender says no, ask a manager to confirm. Sometimes it genuinely can't be done on a given investor's pool, and sometimes a front-line rep just doesn't know it's allowed. You want a real answer, not a reflexive one. There's also no rule that the credit must be shoved entirely into points, and points-by-default is the structure we'd question first. You can usually split the credit, part toward the rate and part toward closing costs, so you show up needing just your down payment. Ask your lender to lay out the options in writing on an updated Loan Estimate so you can see exactly where every dollar of that credit goes, then pick the structure that fits you. The credit is your own money, financed into the price of the house, so spend it deliberately.