{"iri":"https://lexicon.financial/ext/uscode/us/usc/t26/s6603/d/3/B","label":"30-day letter","definition":"The term “30-day letter” means the first letter of proposed deficiency which allows the taxpayer an opportunity for administrative review in the Internal Revenue Service Independent Office of Appeals.","license":"https://www.usa.gov/government-copyright","source":"tax","source_url":"https://uscode.house.gov/browse/prelim@title26"}