The incorporation rule follows the company, not you
UK company residence rests on two rules. First, the incorporation rule: a company formed at Companies House is UK tax resident from incorporation, a statutory rule originally in Finance Act 1988 section 66 and now in section 14 of the Corporation Tax Act 2009. Your personal move abroad does not touch it. Second, the case-law central management and control test from De Beers Consolidated Mines v Howe (1906): a company resides where its real, top-level control actually abides. That test is what drags foreign-incorporated companies into the UK, but it also works in reverse when you emigrate, because the country you move to will typically apply its own place-of-effective-management rule to a company you now run from its territory. The result is that a UK Ltd run from abroad can satisfy two countries' residence tests at once.
Treaty non-residence is the only exit, and it is no longer automatic
Where both countries claim the company, the double tax treaty tie-breaker in Article 4 decides which one is treated as the residence country, and if it awards residence to the other state the company is treaty non-resident and, under CTA 2009 section 18, not UK resident for tax purposes. Historically most treaties settled this automatically by place of effective management. For treaties affected by the OECD Multilateral Instrument that automatic rule is gone: the two competent authorities must agree the company's residence by mutual agreement, having regard to effective management, incorporation and other factors, with effect for UK corporation tax from 1 April 2019 at the earliest depending on each partner's ratification. Until they agree, the company can be denied treaty benefits, and HMRC will not apply the treaty non-resident outcome unilaterally. So becoming non-resident is a slow, uncertain government-to-government process, not a box you tick.
What to actually do when you move
For most owner-managers the realistic choices are to keep the company UK resident and manage the overseas exposure, restructure, or close it before you go. Running a UK company from abroad is workable with care, but where the board has genuinely moved, the residence question should be checked before it becomes a dispute, and dual residence deliberately designed out. If the company has served its purpose, closing it before you leave is often cleaner than testing a tie-breaker. Remember too that even a company that does become non-resident stays taxable on profits attributable to a UK permanent establishment, as defined in CTA 2010 section 1141. Horizon advises on company residence and cross-border structures for a fixed fee agreed upfront, and a free clarity call will tell you quickly which route fits your move.