Retroactivity of taxes on BTPs following relocation

Hi everyone,

I am writing to ask for advice regarding my financial situation, as I haven't been able to find certain answers so far.

My situation:

• One week ago, I moved to Sweden from Italy, officially notifying Sweden (I have started the residency application process).
• I have not yet registered with AIRE (Registry of Italians Residing Abroad).
• I have a custody account with Intesa San Paolo, where I hold some BTPs (Italian government bonds).
• Since January 1st, 2026, I have received coupons from the BTPs I own.

From what I know, since I will spend fewer than 183 days in Italy in 2026, I will be considered a tax resident in Sweden for the entire year of 2026.

I should also add that Sweden taxes all capital gains at 30% and that there is a double taxation treaty between Italy and Sweden.

My questions are:

1. In the tax return I will file next year here in Sweden, will I have to pay the missing 17.5% in taxes to reach the 30% total on coupons earned this year before I even set foot in Sweden? In other words: is there retroactivity on tax payments in the event of a change in tax residency during the same year?
2. If I wanted to sell everything TODAY to close the custody account (Intesa San Paolo is not yet aware of my move), would anything change? Because formally, Sweden knows I arrived last week, but I am not yet officially a Swedish resident. Would it be treated as if I had sold everything before moving here?

I hope I have been clear. Thank you very much for your answers.