You have incorporated an Irish company, received its certificate and started opening supplier accounts. Then one form asks for a company registration number, another asks for a tax ID and a courier requests an EORI. Copying the same number into every box can create delays or misrepresent a registration that has not been completed.
This guide answers a narrower question than our general tax-registration checklist: which Irish company identifier belongs in which situation, and how do you establish what is actually active? It covers CRO numbers, Revenue tax references, VAT and customs identifiers, plus the personal numbers sometimes requested during formation. Official guidance was checked on 11 October 2026. The examples are fictional; transaction-specific tax treatment and overseas obligations require appropriate advice.
Start with the purpose, not the shape of the number
A business number is useful only when it is connected to the right entity and system. CRO incorporation, Revenue registration and customs setup answer different questions. Two identifiers may look similar or share an underlying reference, but that does not make their registrations interchangeable. A reference alone is not evidence that every tax head is active.
Use the comparison below as a routing tool, not as a way to manufacture a missing number. If an application uses a vague label such as tax ID, ask its support team which Irish identifier it accepts and why it needs it. Save that answer with the application so another person does not later replace a correct entry with an unrelated number.
| Identifier | Main purpose | Where to confirm it |
|---|---|---|
| CRO number | Company identity on the corporate register | Incorporation certificate and CRO CORE |
| Revenue TRN | Company tax record and returns | Revenue correspondence and relevant ROS record |
| VAT number | VAT registration and relevant transactions | Revenue confirmation; VIES for intra-EU validation |
| EORI | Customs identification for goods entering or leaving the EU | Issued EORI and official validation |
| PPSN or IPN | An individual's identification for the relevant process | Issuing authority and approved personal records |
What is a CRO number, and how can you find it?
For an Irish company, the CRO number is its company registration identifier. Check the Certificate of Incorporation and match the entry on CRO CORE. The official search accepts an entity name or register number and covers companies, business names and limited partnerships. Check the entity type as well as the name: a registered business name is not itself proof that an LTD has been incorporated.
Use the exact registered company name when reconciling a contract, onboarding pack or company record. A brand can differ from that name. Where a company trades under another name, explain which legal entity stands behind it rather than presenting the brand's registration as a second company. Our multiple-businesses guide explains that distinction in more depth.
The CRO number is appropriate for an Irish company-registration field. It is not evidence of a tax registration, commercial licence, bank approval or the reliability of a prospective supplier. A directory result can help you identify a counterparty, but use the official register and the relevant original documents when formal evidence is required.
What does a Revenue Tax Reference Number establish?
Revenue issues a Tax Reference Number, or TRN, when a company registers for tax. Revenue also explains that the company's TRN is separate from the founder's personal tax affairs, which are dealt with under their PPSN. Do not substitute the director's personal number simply because the company has not yet completed its registration.
Keep the company's registration confirmation, applicable tax heads and effective dates together. The useful record is not just a string copied into a spreadsheet: it is a reference plus evidence of what Revenue has registered. Ask your accountant to explain which entries are active, which are still pending and whether further evidence has been requested.
For example, a fictional consultancy may have a Corporation Tax registration while its VAT application is still under review. A supplier asking specifically for a VAT number is not asking whether a company tax record exists. Describe the actual status and ask how the supplier handles a pending application; do not relabel the available TRN as proof of an approved VAT registration.
Why a CRO number is not a VAT number
Company incorporation does not establish VAT registration. Whether registration is required or available depends on the activity and relevant rules. Revenue's guidance includes obligatory registration, elections to register and situations involving purchases from abroad. A business should assess those questions rather than register merely to fill a mandatory-looking supplier field.
Check the actual Revenue confirmation and effective date before describing an identifier as an active VAT number. Do not add IE to the CRO number or guess a suffix. If your accountant says the business does not need a particular registration, ask the supplier or platform for its appropriate non-registered route. Its form design does not decide your tax obligations.
For an application still pending, preserve the submission evidence and any follow-up request. Agree who will monitor the response and who will update the customer or supplier once the position is confirmed. Do not promise approval on a date selected to fit a launch campaign. Treat registration support and the authority's decision as separate stages.
Domestic VAT, intra-EU status and a failed VIES check
Revenue distinguishes Domestic-only and Intra-EU VAT registration. Approved Intra-EU registration is entered on VIES; Domestic-only customers can apply for Intra-EU status when their activity requires it. A domestic registration should not simply be presented as confirmation that an EU cross-border check will pass.
The European Commission explains that a negative VIES result can arise because a number does not exist, intra-EU activation is missing or registration is not finalised. Updates may not appear immediately. An unavailable system is also different from an invalid result. Preserve the check and seek national confirmation where necessary rather than concluding that the company does not exist.
As a practical troubleshooting sequence, compare the entered number with the issued record, confirm the requested registration status with your adviser and record the result and time of the check. If the number validates but a supplier's own form still rejects it, send that supplier the relevant validation evidence and ask it to investigate. Do not use someone else's identifier to bypass the error.
When a courier or customs agent asks for EORI
EORI is the customs identifier used by traders importing goods into or exporting goods out of the EU. Revenue says ROS registration is needed before applying and that the official address must include its Eircode. Some historical EORI registrations were aligned with VAT numbers, but a resemblance is not a reason to assume a new company already has one.
Confirm the issued EORI and validate it before giving it to the customs representative. A fictional online retailer importing stock should identify which company is the importer, whose EORI will be used and who will prepare the declaration. This exercise also exposes a common entity mismatch: goods purchased by one business while another entity's identifier appears on the shipping paperwork.
Do not treat an EORI as approval for a product or as completion of every customs obligation. Our dedicated EORI guide covers the wider preparation. If you only provide remote services, do not order a customs registration just because a generic vendor form contains an EORI box; clarify the transaction and the reason for the request first.
PPSNs and IPNs belong to people, not the LTD
A PPSN is a personal identifier issued by the Department of Social Protection. CRO guidance describes an IPN as an identification route for eligible directors or beneficial owners without a PPSN, used for relevant CRO/RBO filings. Neither should be placed in the company's public registration-number field or offered as its VAT number.
For a legitimate identification request, ask who requires the number, for which process and through which secure channel. Avoid putting personal identifiers into public website footers, shared marketing documents or routine supplier replies. A founder's identity pack and the company's public-information pack should be separate. Follow the applicable authority's instructions rather than collecting every possible number into one widely shared file.
Which number goes on the website, invoice or onboarding form?
For an Irish limited liability company's website, CRO guidance requires the name and legal form, place and number of registration, and registered-office address on the homepage or a readily accessible page identified from it. It also gives disclosure rules for business letters and order forms. Keep these corporate disclosures distinct from a VAT invoice's requirements.
Revenue's VAT invoice guidance includes the supplier's registration number and, for specified transactions, the customer's VAT number. A CRO number does not replace the required VAT identifier. Conversely, a website showing a VAT number still needs the relevant company disclosures. Ask your adviser to check the template against the real transaction, not just whether two number fields are present.
Onboarding forms are more variable. Label your record pack clearly: legal company name, company registration number, registered office and separately confirmed tax identifiers. If a platform requests a foreign concept such as an employer identification number, ask for its documented Irish-entity procedure. Do not promise account acceptance: a correct number is only one part of a provider's review.
Prepare a registration-status pack before requesting help
Make one controlled company-status sheet with links to the original evidence. Record the legal entity, each confirmed registration, effective dates, pending applications, follow-up owner and the next action. Use pending or not applicable only where that accurately describes the position. Do not let a blank field become an invented registration.
For the registration itself, Revenue requires a CRO number for a new company. Its company-registration guidance routes represented companies through the agent's ROS application and describes TR2 or TR2 (FT) for unrepresented companies as appropriate. Separate VAT guidance has its own online and exceptional paper routes. Choose the current route for the actual applicant and tax head with your adviser; a foreign shareholder alone does not answer every residence or establishment question.
- Exact legal name, CRO number and incorporation certificate.
- Business activity, proposed trading date and customer/supplier countries.
- Confirmed registrations and effective dates, with original evidence.
- Pending application references and unanswered information requests.
- The exact form or supplier question causing the difficulty.
- A named person responsible for the next follow-up and ongoing filings.
How StartCompany.ie can help with the next step
If the company exists but its Revenue setup is incomplete, review our tax-registration service. The published scope covers applicable registrations, ROS setup and guidance on obligations. Explain what you already have and what is still pending so the team can assess the relevant work, rather than assuming you need every registration mentioned in this article.
Review the service scope and current total payable before ordering. Payment is not Revenue approval, a fixed processing deadline or a commitment that a bank or marketplace will accept the company. Ask separately about any customs work or ongoing returns you need; do not assume EORI support or continuing accounting is included in a tax-registration order. If incorporation has not happened yet, compare the formation packages first.
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Official information and next steps
Official guidance checked on 11 October 2026. Practical examples and record-pack suggestions are illustrative, not personalised tax or legal advice. Confirm current registration routes, transaction rules and service scope before acting.
- CRO: entity search services
- Revenue: Tax Reference Numbers
- Revenue: registering a new company
- Revenue: companies and separate tax records
- Revenue: VAT registration eligibility
- Revenue: how to register for VAT
- Revenue: Two-Tier VAT
- European Commission: VAT validation through VIES
- Revenue: EORI system
- Revenue: PPSNs
- CRO: eligible beneficial owners without a PPSN
- CRO: corporate disclosures
- Revenue: VAT invoice information