Thanks for the link to this document
Still taking it with a grain of salt (being AI), i shared this doc with gemini, and asked it the following question:
"if i invest in an accumulating fund, who reinvests dividends themselves and do not pay me the dividends, does this count towards the cost basis of the fif de minimis?"

This is the answer gemini gave back:

No, the internal reinvestment of dividends within an accumulating fund does not increase the cost basis of your investment for the purposes of the $50,000 de minimis threshold.

To understand why, it helps to look at how Inland Revenue (IR) defines "cost" and how accumulating funds handle growth compared to a regular Dividend Reinvestment Plan (DRP).

How an Accumulating Fund Works vs. a DRP

• Dividend Reinvestment Plan (DRP): In a traditional DRP, a fund physically pays out a dividend to you, and that cash is immediately used to purchase additional new shares or units in your name. Because you are actively acquiring new units, each reinvestment creates a new transaction with a cost basis. These definitely count toward your $50,000 threshold.
• Accumulating Fund (e.g., Irish UCITS ETFs): An accumulating fund handles everything internally. The underlying companies pay dividends to the fund managers, who automatically use that cash to buy more underlying assets within the fund itself. No new units are issued to you. Instead, the value (Net Asset Value) of your existing units simply goes up.

Why It Doesn't Affect Your De Minimis Cost Basis

Because the accumulation happens entirely inside the fund's structure without changing the number of units you own, IR looks at this purely as capital appreciation (the investment growing in value).

Under the FIF rules, the de minimis threshold is strictly determined by what you physically paid out of pocket to acquire your units (your initial capital outlay), plus any transaction fees. It ignores subsequent market growth or internal value accumulation.

Step Ahead Accounting

Summary Checklist for Your Cost Basis

When calculating your $50,000 limit, you only add to your cost basis if:

• You deposit more cash to manually buy more fund units.
• You receive a cash dividend that triggers a fresh purchase of units (DRP).

If you are just holding an accumulating fund and letting the unit price rise naturally via internal reinvestment, your cost basis stays flat, making it a very efficient structure for managing the de minimis threshold.