Your Certificate of Incorporation lands in your inbox and it feels like the finish line. You picked a name, appointed directors, filed the A1, and now you're officially a limited company. The certificate isn't the finish line though, it's a starting gun. A set of new deadlines starts ticking the moment it arrives, spread across three different government bodies. Miss one and it costs real money, not just an awkward email.
In short
The 30-day clock: registering for tax
Incorporation and tax registration are two separate processes. The CRO creates your company. Revenue has to be told separately that it exists and has started trading.
Under section 882 of the Taxes Consolidation Act, file a Statement of Particulars with Revenue within 30 days of starting to trade. The clock starts from your first trading activity, not the certificate date, so a company incorporated in March that doesn't invoice until June has until 30 days after June to file.
At the same time, register for Corporation Tax using Form TR2 through ROS. If an accountant handles this for you, they'll usually file it through their own ROS access. Do both together and tax registration is one thing you won't have to think about again until your first return.
The RBO deadline nobody remembers
Separately from Revenue, every Irish company has to register its beneficial owners, meaning the individuals who ultimately own or control it, with the Register of Beneficial Ownership (RBO). A newly incorporated company has 5 months from the date of incorporation to file this. It's a short online form, but it sits outside your usual tax and CRO calendar, so it's the one people genuinely forget about.
Your first B1: exactly 6 months, and it arrives fast
This is the deadline that trips up the most new companies. Every Irish company must file an annual return (Form B1) with the CRO. Your first one is due exactly 6 months after incorporation, and unlike every return that follows, this first B1 does not require financial statements.
Miss it and the CRO charges a late filing fee of €100, plus €3 a day, up to €1,200 per return. There's a bigger consequence behind the fee too. Since 16 July 2025, a company only loses its audit exemption if it files an annual return late more than once in a five-year period. Under the old rule, one late return cost the exemption immediately; that's no longer true, but a second slip within five years still costs it.
VAT and PAYE: only when they apply, but plan ahead
You don't need to register for VAT or PAYE the day you incorporate. You just need to know exactly when each becomes compulsory.
VAT registration is required once you expect turnover to pass €42,500 for services or €85,000 for goods. When you register, you'll also choose between a Domestic-only or an Intra-EU VAT registration, depending on whether you trade with businesses elsewhere in the EU.
For PAYE, if you or anyone else will draw a director's salary, you must register as an employer and operate PAYE first, even for a single-director company with no other staff. Paying yourself before that registration is in place is one of the most common, and most easily avoided, mistakes we see.
Trading under a different name
If your company will trade under a name other than the one on its certificate (a shop name, a brand), that name needs its own registration. File Form RBN1B within 1 month of starting to use it; the online fee is €20. Skip this step and you're technically trading under an unregistered business name.
Your first year of Corporation Tax
New companies get one genuine break. If your Corporation Tax liability for the first accounting period comes in under €200,000, which covers most new small companies, you don't pay preliminary tax for that period.
You still have to file and pay, though. Your CT1 return, and any tax due, is owed within 9 months of your accounting period end, by the 23rd of that ninth month if filing through ROS. No preliminary tax obligation does not mean no return. Plenty of directors read the exemption and stop paying attention until the CT1 catches up with them.
Two things nobody will fine you for, but should still do
Open a business bank account before your first invoice goes out and keep it completely separate from your personal account. Start bookkeeping from day one instead of reconstructing a year of receipts from memory in month eleven. Neither is a legal deadline. Both are the difference between a straightforward annual return and a stressful one.
What this means in practice
Say you incorporate on 1 August 2026 and start trading the same day.
VAT only enters this timeline once turnover looks set to cross €42,500 (services) or €85,000 (goods); there's no fixed date, only a threshold to watch.
Common mistakes
Next steps
If your certificate has just landed and you'd rather not track deadlines across three different portals on your own, we can take that off your plate. We handle Revenue and RBO registrations, the first B1, and payroll setup for newly incorporated companies across Limerick and beyond. Get in touch and we'll map out exactly what's due, and when, for your company.