From Longman Dictionary of Contemporary Englishbe next in linebe next in lineAFTERto be the next person, especially to have a job or position → next
Examples from the Corpus
be next in line• You were born to your parents because, right at that moment when they Did It, you were next in line.• As a lad, Cloud and his two brothers were next in line for the Frankish throne.• Hull, as secretary of state, is next in line to become governor.• Prince Charles is next in line to become king of England. 