Treaty on the Functioning of the EU
This treaty sets out the:
- general principles governing budget procedures and the principle of sound financial management (Article 310);
- principle of funding the budget from own resources (Article 311);
- multiannual financial framework – annual expenditure ceilings for at least 5 years (Article 312);
- schedule for the financial year (Articles 313-316);
- procedures for budget implementation and control, and confers the necessary powers (Articles 317-319).
See here articles 310-324 in the Treaty on the Functioning of the EU:
Treaty on European Union
Largely addresses the budget for funding the EU's common foreign and security policy.