Bar on subsequent settlement applications prevents reapplication after penalty for concealment, conviction, or remittance to assessment. A substituted provision bars further settlement applications where an earlier settlement resulted in imposition of a penalty for concealment, where the applicant was subsequently convicted in relation to that case, or where the Settlement Commission returned the case to the assessing officer under the transitional circumstance; additionally, an applicant whose post-amendment application has been allowed to proceed is precluded from later applying under the alternate post-settlement procedure.