VAT Registration in Ireland: When Must You Register?

VAT in Ireland trips up more founders than any other tax. The thresholds are surprisingly low, the rules around services-vs-goods are subtle, and registering at the wrong time can cost you real money — either by registering too early and adding 23% to your prices, or registering too late and owing back-VAT plus penalties.

This guide explains exactly when you must register, when you might want to anyway, and what changes once you do.

The thresholds

The thresholds apply to rolling 12-month turnover, not the calendar year. If your turnover exceeded €42,500 in any 12-month window — even if it crossed in November but the calendar year is fine — you must register.

You also need to register prospectively if you reasonably expect to exceed the threshold in the next 12 months. Don't wait until you've actually crossed it.

Services vs goods — why it matters

The €42,500 services threshold is much lower than the €85,000 goods threshold. Most founders running consultancies, agencies, SaaS businesses or freelance practices hit it within 6–12 months of trading.

Some businesses are clearly one or the other:

• A web design agency = services
• An e-commerce shop selling t-shirts = goods

Others are mixed. A SaaS business selling a digital product is generally treated as services. A business selling physical hardware bundled with software services may need to apportion.

If you're a mixed-supply business, the lower threshold (€42,500) applies once your services component crosses it.

Distance selling — the €10,000 trap

If you're a non-Irish EU business selling to Irish consumers (B2C), the €10,000 threshold is now EU-wide rather than per-country. Cross it and you must either:

1. Register for VAT in every EU country you sell into, or
2. Register for the Union One Stop Shop (OSS) scheme in your home country

Most cross-border SMEs use OSS. If you're a UK business post-Brexit selling to Irish consumers, you likely use the Import OSS (IOSS) scheme for low-value goods, or register for Irish VAT directly.

Voluntary registration

You can register voluntarily below the threshold. Pros and cons:

Pros:

• Reclaim input VAT on business purchases (rent, software, professional fees, equipment)
• B2B customers don't care about VAT — they reclaim it
• Looks more "real" if you're invoicing big businesses

Cons:

• 23% added to prices for B2C customers (most bear this — you can't pass it on)
• Quarterly or bi-monthly returns to file (admin overhead)
• Cash flow timing issues (you collect VAT, then remit it 1–2 months later)

Rule of thumb: if more than 70% of your customers are VAT-registered businesses, voluntary registration almost always pays. If most are consumers, hold off until you must.

What rates to charge

Charging the wrong rate is one of the most common Revenue audit findings. If you're unsure, the Revenue VAT rates database has searchable per-product rulings.

Filing returns

Once registered, you file bi-monthly VAT returns by default (Jan-Feb, Mar-Apr, etc.). Each return is due by the 19th of the month after the period (23rd if you file via ROS).

You can apply to file:

• Quarterly if your annual liability is under €3,001
• Annual if under €5,001 (admin liability — most businesses prefer bi-monthly)

You also file an Annual Return of Trading Details (RTD) that summarises sales and purchases by VAT rate. Due 23 days after your accounting period end.

Reverse charge — the most missed rule

If you buy services from a non-Irish EU business (or a business outside the EU), the reverse charge mechanism applies. The supplier doesn't charge VAT; you account for it both as output VAT (T1) and input VAT (T2) on the same return — net zero, but it must be declared.

Common reverse-charge scenarios:

• Buying software from a US SaaS provider (Adobe, AWS, Stripe — they don't charge Irish VAT)
• Hiring a UK consultant
• Paying Google or Meta for advertising

Forgetting to reverse charge is the #1 finding in Revenue audits of small Irish businesses. AccountsOS detects these from supplier names automatically.

How to register

Registration is via ROS:

1. Sign in with your digital cert (or your accountant's)
2. Go to "Manage Tax Registrations"
3. Choose "VAT" and complete the application (TR1 for individuals, TR2 for companies)
4. Provide expected turnover, types of supply, and your Irish-resident bank account
5. Revenue typically issues your VAT number within 5–10 working days

You can ask Revenue to backdate registration to your trading start date if you missed a threshold breach. You'll owe back-VAT, but you can also reclaim input VAT for the same period.

After you register

Day-to-day VAT obligations:

• Issue VAT invoices showing your VAT number, rate, net, VAT and gross
• Keep VAT records for at least 6 years
• File bi-monthly VAT3 returns via ROS
• File annual RTD
• Pay by direct debit or bank transfer through ROS

A direct debit arrangement spreads the bi-monthly liability across 12 equal monthly debits — useful for cash flow.

Penalties for not registering

If you should have registered and didn't:

• Back-VAT owed from the date you should have registered
• Daily interest at approximately 8% per year on unpaid VAT
• Penalties up to 100% of the VAT due if Revenue treats it as deliberate default
• VAT registration backdated by Revenue (you owe the historic VAT and may not be able to bill customers for it)

Don't be the founder who finds out at audit. Track turnover monthly.

How AccountsOS helps

AccountsOS is live in Ireland and tracks your rolling 12-month turnover automatically. When you cross 80% of either threshold, Finn raises a flag with a link to the registration form. Once registered, the platform:

• Categorises every transaction by VAT rate
• Flags reverse-charge purchases automatically
• Generates the bi-monthly VAT3 return
• Prepares the annual RTD
• Files directly to ROS (subject to ROS API access — manual upload for now)

Try AccountsOS free or read about AccountsOS in Ireland.

Related reading

• Corporation Tax in Ireland: 2026 guide
• Setting up an Irish Limited Company
• PAYE, PRSI and USC explained