The UK Intellectual Property Office and IP Minister Sam Gyimah MP jointly announced the ratification this afternoon on the UK government's news website. We had known for some weeks that the ratification documents were with the Foreign & Commonwealth Office for signing, and deposit with the EU Council’s General Secretariat.
The government press release is keen to emphasise that the UPC agreement is an international treaty, rather than an EU instrument. However, it also notes that the UK’s future relationship with the Unified Patent Court will be subject to negotiation with European partners as we leave the EU.
Ratification brings the UPC a step closer, with the UK hosting the Court’s central division dealing with life sciences patents, and also a local division. However, the UPC cannot start until Germany also ratifies, and that remains on hold pending a complaint to Germany's Federal Constitutional Court. The timescale of that complaint remains uncertain.