Where the other SED qualifications apply, a client correctly used HMRC's Helpsheet 205 to calculate the eligible period showing that at midnight he was absent from the UK because he was outwith the UK territorial 12-mile limit (effect of S.41 ITEPA 2003). His shipmates then, apparently, claimed SED for all the days outwith the 12-mile limit. However, my understanding is that the SED only applies to "overseas" earnings. The actual SED to be allowed is a separate calculation AFTER establishing the eligibility (the chart in HS 205). This SED calculation must therefore be restricted to relieving pay for employment duties undertaken outwith the Continental Shelf Act 1964 (as extended by designated areas) i.e. effectively the so-called 200 mile limit. Therefore, SED cannot be given to pay between the 12 and 200(sic) mile limits. I believe this is a common misconception as the HMRC examples don't make this at all clear. Am I right?