Ireland: the one country where a VAT number does not stop Etsy charging VAT on its fees
Across most of the world Etsy operates a simple rule on its own fees. Give it a valid VAT number and it stops charging you VAT, issuing an invoice each month confirming none was charged, because the supply reverse-charges and you account for it yourself.
Ireland is carved out of that. Etsy's own list of countries where VAT applies to seller fees regardless of whether you have submitted a VAT ID includes Ireland, and its entry for the rest of the bloc reads, in terms, "the EU (excluding Ireland)".
The reason is structural rather than punitive. Etsy Ireland UC is the contracting entity, named as such on Etsy's own documentation. So for an Irish seller the fees are a domestic supply from one Irish business to another, and a domestic supply has no reverse charge available. There is nothing to opt into and nothing to fix in your settings.
What that actually costs you
Less than it first appears, provided you are registered.
A VAT-registered Irish seller pays the VAT on Etsy's fees and then recovers it as input VAT in the ordinary way, so the cash-flow timing changes but the final cost does not. The seller genuinely worse off is the one below the registration threshold, who is charged the VAT and cannot reclaim a cent of it, and who is therefore paying more for the same Etsy services than an unregistered German or Dutch seller in the same position.
That is a real argument for registering earlier in Ireland than you might elsewhere, and it is worth putting through this calculator both ways before deciding.
Everything else is ordinary euro-zone
The rest of the Irish schedule holds no surprises. Processing is 4% plus EUR 0.30, the same as Germany, Finland and the Netherlands. The transaction fee is the usual 6.5% and Offsite Ads the usual 15%. Ireland pays no regulatory operating fee, unlike Britain, France, Spain and Canada, and it is not among the countries Etsy charges a deposit fee.
One general caution: Etsy publishes no VAT percentage for its fees in any country. Its schedule says only that VAT "may vary". Whatever rate applies to you comes from Revenue, not from Etsy, so confirm it there.