# EORI glossary

> Short definitions of the terms used in EORI guidance, with the official source for each: economic operator, UCC, CDS, AEO, XI, carrier, invalidation and more.

- Canonical URL: https://eorilookup.com/glossary/
- Source: [European Commission, EORI guidance document; HMRC EORI guidance](https://taxation-customs.ec.europa.eu/document/download/bbe4c653-3b6d-4bed-932c-61bb77711384_en?filename=EN_EORI%20Guidance%20document.pdf)
- Checked: 2026-10-21

Definitions restate the sources. Where a source does not define a term, the entry says so.

**EORI** – Economic Operators Registration and Identification number. A unique identifier in the EU customs territory, assigned to an economic operator or other person for customs purposes ([guidance](https://taxation-customs.ec.europa.eu/document/download/bbe4c653-3b6d-4bed-932c-61bb77711384_en?filename=EN_EORI%20Guidance%20document.pdf), Art. 1(18) UCC DA).

**Economic operator** – A term defined in Article 5(5) of the Union Customs Code. The guidance lists who counts and who is only an "other person".

**Person** – Defined in Article 5(4) of the Union Customs Code. Only a legal person or an association with legal capacity can receive an EORI number.

**Permanent business establishment** – Defined in Article 5(32) of the Union Customs Code. It matters for deciding where an operator is established.

**UCC** – The Union Customs Code. The guidance cites it for the rules on registration and invalidation, for example Article 9.

**Registering authority** – The customs authority that assigns the number. The Commission publishes a [search for registering authorities](https://ec.europa.eu/taxation_customs/dds2/eos/ra_consultation.jsp).

**Invalidation** – The act of making a number invalid, at the holder's request or when the activities stop. The data is kept for 10 years.

**XI** – The prefix of EORI numbers issued by HMRC to operators for Northern Ireland. GOV.UK does not define the prefix in detail; it says GB and XI numbers are in HMRC's database ([HMRC](https://www.gov.uk/guidance/economic-operators-registration-and-identification-eori/finding-and-checking-an-eori)).

**GB** – The prefix of EORI numbers issued by HMRC to UK-established operators.

**CDS** – The Customs Declaration Service of HMRC. A GB EORI is needed to use it, and the holder can find the number in its financial dashboard.

**AEO** – Authorised Economic Operator. The guidance says an EORI number is required to obtain AEO facilitations.

**Entry summary declaration (ENS) and exit summary declaration (EXS)** – Declarations listed by the Commission as ones that make a non-EU operator need an EORI. The sources we read do not define them further.

**Temporary storage declaration** – A declaration listed in the same way. Not further defined in the sources we read.

**Carrier** – An operator that moves goods. The Commission names carriers by sea, inland waterway or air as needing registration if not established in the EU.

**Declarant** – A role in customs declarations. The number is mandatory or conditional in the declarant data field.

**TCUIN** – Third-country unique identifier. The guidance says it may be used where a recognised trader partnership programme applies; it is not an EORI.

**ATA and CPD carnets** – International customs documents. EU-established holders must be registered, and the number goes in box A or box 1.

**Indirect representative** – A person who deals with customs on another's behalf. HMRC says a business that cannot register can appoint one, and that the representative needs their own EORI.

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