I'm in a similar situation — building a SaaS (API proxy for LLM cost optimization) and evaluating Estonia vs UK LTD. Leaning towards UK for Stripe compatibility but the 0% tax on retained profits in Estonia is very tempting. Would love to hear from anyone who's used both.

The 0% tax on retained profits is nice as long as your own residency country does not try to tax it. Some countries like the US don't consider this as a shelter and if you are the beneficial owner then still want to tax your company profits there.

Also the 0% retained profits system will come to an end in the next few years due to a worldwide push to have minimum corporate income tax.