The Tax tracker follows HMRC Helpsheet HS205's eligible-period method for the Seafarers' Earnings Deduction — the day-counting rules that decide whether your foreign earnings qualify to be exempt from UK tax. It's a running record you keep as you go, not something you reconstruct from memory in January.
The first time you open Tax, SeaLog asks you to confirm you understand the tool is for record-keeping and estimation only — it isn't a substitute for professional tax advice, and its exports aren't a submission to HMRC.
Add a departure date and, once you're back, a return date. SeaLog applies HMRC's departure/return "midnight rule" and tracks whether the voyage begins or ends at a foreign port — both feed directly into the eligible-period calculation.
If you're on a fixed rotation, use "Import from my rotation" to turn your onboard schedule into a set of reviewable trips in one tap — adjust any dates that don't match what actually happened before adding them to your log.
SeaLog tracks the 365-day qualifying period and the 183-day single-visit limit for time back in the UK, and flags where a visit runs close to breaching it — the same checks HMRC applies when it reviews an SED claim.
Export a supporting record at any point in the tax year. It's formatted to keep with your Self Assessment and hand to HMRC or your accountant on request — always have a qualified accountant verify the figures before you submit.
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