Each bank’s policies are written differently. I recommend including the changes in the policy where they are the best fit at your bank (at most banks this would probably be the Loan Policy, but it might be different at your institution) and reference it in the other policy. So for example, you would incorporate the specific updates into your Loan Policy and make reference to complying with “applicable lending regulations as outlined in the the Loan Policy” or incorporate it into your Compliance Policy and in your Loan Policy state that you will “comply with applicable regulations as detailed in the Compliance Policy.”
