The APR takes into consideration some of the closing costs such as points, lender fees, broker fees, etc. When a broker provides you with the Truth In Lending (TIL) the APR is calculated from the Good Faith Estimate of closing costs. If your Broker did not include all of the costs the APR will be lower than it is on the final TIL. If there is a big difference this usu the Broker left off a large fee.
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