General guidance for sponsors, biotechs and CROs. It is not advice on a specific study; timelines and requirements change, and every submission should be checked against the current regulator guidance.
Most submission delays are not caused by the regulator. They are caused by an application that was not ready on the day it was submitted. Our full checklist sets out what 'ready' means for a clinical trial application under the EU Clinical Trials Regulation (Regulation (EU) No 536/2014) through CTIS, and for the UK under the reformed clinical trials regulations in force since 28 April 2026. Below is one worked example and a summary of the other areas it covers.
Example from the full checklist
Legal presence
EU/EEA: a sponsor not established in the EU/EEA must appoint a legal representative established there. Some countries allow a local contact person instead for trials run only on their territory (or there and outside the EU/EEA), subject to national rules that may require prior approval; Ireland does not offer this option. UK: the sponsor or its legal representative must be established in the UK or an MHRA-approved country, which currently comprises the EU/EEA countries only. Confirm both early, as appointing a representative can take time.
Sources: Regulation (EU) No 536/2014, Article 74 (EUR-Lex) (opens in a new tab); UK regulation 3(11)–(11A), Medicines for Human Use (Clinical Trials) Regulations 2004 (opens in a new tab); MHRA approved-country list (opens in a new tab); HPRA guide to clinical trials under the CTR in Ireland, section 3.7 (opens in a new tab).
Also covered in the full checklist
Part I dossier
Part I is common to all Member States concerned and assessed under the reporting Member State's lead, so a gap can delay every country: submit it complete. The GMP documents required depend on the product's authorisation status, whether it is modified and where it is made.
Full detail on request
Ireland
One CTIS application covers the regulatory and ethics assessment in Ireland; site contracts and local approvals run separately, on their own timelines.
Full detail on request
UK
The reformed UK clinical trials regulations took full effect on 28 April 2026, and the review pathway that applies to your trial can affect your timeline.
Full detail on request
Transparency
CTIS publishes key documents, such as the protocol, on category-dependent timelines, so prepare 'for publication' versions, redacted where needed, before you submit.
Full detail on request
This page is based on Regulation (EU) No 536/2014, the UK Medicines for Human Use (Clinical Trials) Regulations 2004 (as amended, including by SI 2025/538, in force from 28 April 2026), and official guidance from the European Commission, EMA, MHRA, HPRA and NREC.
Get the full submission readiness checklist
The example above shows the level of detail. The full checklist runs from preparation to post-approval: before you submit, Part I, Part II, the UK route and after submission. It includes ten questions to ask your team, the regulatory sources, and notes for Ireland and the UK. Request a copy and we'll send it to you personally. If you'd like, we'll also offer a free, no-obligation 20-minute call to talk through your planned submission (no confidential documents needed).
Last reviewed against official sources: 27 September 2026. This page and the full checklist are general information, not regulatory or legal advice.