The European Commission estimates that the FTT will reduce the contributions of Member States to the EU budget by €54bn in 2020. This is based on a projection by the Commission that the FTT will raise €81bn in 2020 and proposes that two thirds of this is used to replace 50% of Member States’ contributions to the EU budget, with the remaining one third being retained by Member States. If the Commission proposals are adopted, then Ireland could reduce its direct contribution to the EU budget in 2020 by €534m while the UK could reduce its contribution by €7,692m.

Using data for 2010, the Commission estimates that the FTT will raise €57bn. Assuming that the volume of taxable transaction will follow the evolution of the EU GNI (gross national income), that €57bn will become €81bn in 2020. The Commission suggests that two thirds of that €81bn be used to finance EU expenditure, which amounts to €54.2bn. Based on the Commission's proposal, the GNI national contributions would be €110bn in 2020 without an FTT. With an FTT, Member States could therefore save 50% of their GNI contribution to the EU budget.

Currently, the EU Budget is funded by the following sources:

• Traditional own resources (15% of the budget, €19.3bn): the oldest kind of resources is collected mainly from customs duties on imports from outside the EU and sugar levies. EU governments keep 25% to cover the cost of collection.
• Own resource from value added tax (VAT) (11% of the budget, €14.5bn): A standard percentage is levied on the harmonised VAT base of each EU country. The VAT base to be taxed is capped at 50% of GNI for each country.
• Own resource based on gross national income (GNI) (73% of the budget, €93.7bn): A standard percentage is levied on the GNI of each EU country. It is used to balance revenue and expenditure, i.e. to fund the part of the budget not covered by other sources of income.

The budget also has other sources of revenue, e.g.: taxes on EU staff salaries, contributions from non-EU countries to certain programmes, fines on companies for breaching competition laws, etc. which account for 1% of the budget or approximately €1.6bn.