9 July 2026 · ETR
Effective Tax Rate & the Top-up
The DMTT top-up is the gap between 15% and your jurisdictional effective tax rate (ETR). The ETR is covered taxes divided by GloBE income for all UAE constituent entities combined. A substance-based income exclusion first removes a return on tangible assets and payroll, so the top-up applies only to "excess" profit. If the UAE ETR is below 15%, the top-up percentage closes the gap on that excess.
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How the ETR is built
The calculation is jurisdictional — all UAE entities are blended together.
- ETR = covered taxes ÷ GloBE income for the UAE.
- GloBE income starts from financial accounts with adjustments.
- A substance-based exclusion removes a routine return.
- Top-up applies to the excess profit above the carve-out.
Closing the gap to 15%
Only the shortfall is charged, and only on excess profit.
- Top-up % = 15% minus the UAE ETR.
- Applied to excess profit after the substance exclusion.
- A DMTT that meets the QDMTT standard takes priority globally.
- Accurate GloBE data is the hard part — not the arithmetic.
Related guides
Frequently Asked Questions
For groups modelling their UAE top-up.
How is the effective tax rate calculated?
Covered taxes divided by GloBE income, blended across all UAE constituent entities of the group.
What is the substance-based income exclusion?
A carve-out that removes a routine return on tangible assets and payroll, so the top-up applies only to excess profit.
Does a 9% UAE rate mean no top-up?
Not necessarily. Incentives, exempt income or the QFZP 0% rate can push the ETR below 15% and create a top-up.
Can Exiloz model our top-up?
Yes. We build the GloBE ETR calculation and quantify any UAE top-up before it hits your return.
Model your top-up before you file
Exiloz builds your GloBE ETR calculation so the DMTT top-up holds no surprises.