Moa verification

Does USP or BP Methods need to be verified? Why ?
While they are credible and official. Plz reply me as soon as possible

MOA verification is required to get confidence on the method developed. If Method verification does not complies than you can challenge. Its as simple as that Vendor of Raw Material proveds specification, MOA, COAs and Stability during vendor qualification but we verify the three pre-purchase samples to get confidence that material and method is complying. same situation is with Pharma methods