EWTN Catholic Q&A
valid but illicit
Question from linda on 04-09-2017:

Would you please explain (in simplest terms) what 'valid but illicit' means and give an example?

Answer by Richard Geraghty on 04-24-2017:

Dear Linda,

Suppose a priest from another diocese says mass in a diocese without getting the local Bishop's authorization. The mass would still be an authentic (valid) mass but it would be illegal (illicit) because it was said without the local Bishop's authorization.

Dr. Geraghty