Both the UK Government and the EU negotiating team have let down vast numbers of EU citizens in the UK. The creation of continuing EU responsibilities in a newly ex-Member State, for EU citizens who exercised their EU free movement rights before withdrawal, is an unprecedented challenge. This piece explores four growing threats to their rights. (1) The conditions laid down in Directive 2004/38 loom large in the Withdrawal Agreement, disproportionately disentitling women and children from a right to stay in their homes. (2) The Withdrawal Agreement contains a dramatic departure from standard practice in EU law, allowing the UK and Member States to make registration constitutive, not declaratory, of the right to stay. It will transform thousands into unauthorized migrants overnight. (3) The UK’s new EU Settled Status is fraught with risks of administrative injustice, which affect the vulnerable most. (4) The UK’s attempt to separate welfare rights from “pre-settled status” forces wide-reaching questions about the clout of Article 18 TFEU. In short, vulnerable EU citizens emerge in this process not so much as bargaining chips but as collateral damage, with the UK government displaying a considerable appetite for, and the EU tolerating, a real risk of large-scale disentitlement.