Moving to Delaware as a journeyman plumber: every state's rule

Delaware does not issue a journeyman or journeyperson plumber license. The Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners licenses only master plumbers (and master HVACR / master HVACR restricted), and 24 Del. C. § 1807(c)(1) lets an apprentice, journeyman, mechanic or other person provide plumbing services without a Board license while working under the supervision of a master plumber who is their employer or a full-time employee of the same business. An out-of-state journeyman plumber license therefore has nothing to transfer to in Delaware and is neither required nor recognized as a Delaware credential for employment. Delaware's own 'journeyman's certificate' in 24 Del. C. § 1808(a)(1) is a certificate of completion from a plumbing apprenticeship that meets or exceeds federal BAT/OA standards, issued in any state: it is an experience credential used toward the Master Plumber license, not a license. With that certificate, two years of post-apprenticeship work under a master plumber (or a similar-level licensee in another state) qualifies an applicant for the master exam; without it, seven years of such supervised experience plus the apprenticeship equivalency (bypass) tests are required. Out-of-state journeyman hours gained under a licensed master count toward those master-exam experience requirements.