The Advisory Group on Market Infrastructures for Securities and Collateral (AMI-SeCo), an advisory body of the Eurosystem whose views do not necessarily represent those of the European Central Bank, has published a report mapping the remaining obstacles to integrating securities post-trade services in the European Union and setting out recommended follow-up actions and responsible addressees. Drawing on a stakeholder survey completed in 2024 and earlier barrier work, it concludes that many long-identified impediments continue to fragment cross-border issuance, custody, asset servicing, clearing and settlement. The report groups barriers into legal frameworks, issuer-investor processes, buyer-seller processes and transversal issues. It highlights high-impact frictions from differences in national securities, corporate and insolvency law (including uncertainty over rights in intermediated securities, corporate-events processing and constraints on the Central Securities Depositories Regulation’s “freedom of issuance”), and from tax processing, where withholding tax reporting, beneficial-owner concepts, relief-at-source availability, liability regimes and operational requirements remain highly divergent despite the Faster and Safer Relief of Excess Withholding Taxes Directive. Operationally, it flags the absence of a trusted “golden source” for securities reference and corporate events data, low compliance with corporate events and shareholder identification standards, continued practical limits on using cross-CSD settlement and choosing settlement location, and fragmented data and messaging practices (including ISO 15022 and ISO 20022 co-existence and inconsistent identifier usage). Recommended actions include renewed EU-wide legal analysis and improved transparency tools (for example, an insolvency-rule repository), tighter and clearer corporate-law disclosures supporting cross-border CSD services, issuer-to-issuer-CSD provision of machine-readable data, wider adoption of common data models and ISO 20022, further settlement-efficiency measures (including consistent use of place of settlement and standard settlement instructions), and a more harmonised “report once” approach to regulatory reporting and KYC/customer due diligence. The paper links some settlement recommendations to preparations for the planned move to a T+1 standard securities settlement cycle by 11 October 2027, proposing reliance on already-identified industry actions where applicable and potential AMI-SeCo monitoring and support beyond the changeover. It also commits AMI-SeCo to establish a framework for tracking progress and monitoring compliance to address the follow-up gap observed after earlier barrier reports.