While Clay offers phone number validation through ClearoutPhone integration to verify if numbers are active and to identify line types (mobile vs landline), there isn't a built-in feature to specifically check if numbers are on the Do Not Call registry. ClearoutPhone can help validate if a phone number is active and correctly formatted, but you'll need to use a separate service to check Do Not Call registry compliance.
Sources:Data points: Mobile Validation | Clay.comClearoutPhone integration overview | Documentation | Clay University