The CFO asks: "Are we above the OECD minimum tax rate
of 15%?"
Simple question. Then reality begins.
- The accounting profit is in one system.
- Tax data sits in ONESOURCE.
- Some adjustments live in spreadsheets.
- A few assumptions are in workpapers only one person understands.
And suddenly a "simple" Pillar Two calculation
isn't so simple.
At first, the tax team isn't worried.
After all, the calculation itself looks straightforward.
- Accounting Profit
- GloBE Adjustments
- Covered Taxes
- Effective Tax Rate (ETR)
- Top-Up Tax
Looks manageable. Then the emails start.
"Can someone confirm which Covered Tax file is the
latest version?"
"Are we using the Q4 adjustment or the revised Q4
adjustment?"
"Who owns the Safe Harbour assessment for
Ireland?"
"Which spreadsheet was used last quarter?"
If you've worked in Finance or Tax, you've probably lived
some version of this story.
What started as a tax calculation has suddenly become a
treasure hunt.
Not because the formula is difficult. Because the data is
everywhere.
One of the biggest surprises for me while learning more
about Pillar Two is that the challenge often isn't the tax logic.
It's the journey to get the data required to perform the
calculation.
Finance owns some of it.
Tax owns some of it.
Local teams own some of it.
And spreadsheets seem to own the rest.
By the time all the pieces come together, the real question
isn't:
"Can we calculate Pillar Two?"
It's:
"Can we trust the calculation?"
Because nobody wants to explain to a CFO, auditor, or
regulator that the answer depends on which spreadsheet was opened.
And that's where Pillar Two becomes interesting.
The organisations that will do this well aren't necessarily
the organisations with the smartest tax professionals.
They're the organisations that can answer questions like:
- Where did this number come from?
- Who approved it?
- What changed since last quarter?
- Can we reproduce this calculation six months from now?
- Can someone else run this process if a key person is on holiday?
In other words, governance starts mattering just as much as
tax expertise.
I often compare it to building a house.
Everybody talks about the finished house. Very few people
talk about the foundations.
Pillar Two reporting is the house. Data ownership, controls,
workflows, approvals, audit trails, and repeatable calculations are the
foundations.
If the foundations are weak, the reporting process will
always feel painful regardless of how good the final report looks.
Which is why I keep coming back to the same conclusion:
Pillar Two is not primarily a reporting exercise.
It's a calculation, governance, and data management
exercise.
The tax calculation may take minutes.
The effort required to gather, validate, review, and defend
the data behind it can take considerably longer.
So the next time someone asks,
"Are we above the OECD minimum tax rate of
15%?"
Imagine having the answer in seconds.
Now imagine being able to trust it.
That's the difference between having data and having
control.
And that's where the real Pillar Two journey begins.
