Capital gains arising outside Malta (for example, gains from selling shares in your company or other investments) are not subject to Maltese tax, regardless of whether they are remitted to Malta or not.
Foreign income (such as dividends, interest, or rental income) is taxable only if remitted to Malta. A minimum tax of €5,000 per year applies to non-domiciled individuals whose foreign income (excluding capital gains) exceeds €35,000 annually but who do not remit any of that income to Malta. This applies if you're following the standard non-dom regime—not the special residence programmes that allow unlimited remittances at a flat 15% tax rate (but with a higher annual minimum).
Under the standard non-dom regime, given the €5,000 minimum annual tax, it makes sense to remit roughly €31,260 of foreign income each year to Malta. This way, you're paying tax on actual income received, effectively "breaking even" rather than paying tax without any remittance.
Hope this clarifies. Malta's residency system remains quite attractive for Europe, especially now that the UK has closed its non-dom option, Portugal faces complications, Spain’s system remains unpredictable, and Italy has introduced absurdly high minimums
To add to what
@Eurocash mentioned, keep in mind that basically anything you spend with your card while physically in Malta—regardless if the card is linked to an EMI or traditional bank abroad—will usually count as a taxable remittance. Honestly, it's not worth taking too many risks here. The only decent workaround I've noticed is that many people set up a Maltese LTD and route certain expenses through it, which is pretty common practice anyway. Having chatted extensively with local Maltese tax advisors and lawyers, the good news is that they all tend to agree Maltese tax authorities are generally quite flexible when it comes to allowable expenses—think of a US-style pragmatism rather than the stricter approach seen elsewhere in Europe.