Consult this publication on line at

Formal annuality:
The budget must deal with a one-year period or (in principle) a two-year
period where each year is treated separately. In practice, the latter provision has not been
applied to the federation.
Practical multi-annuality:
The budget must be accompanied with a five-year Financial
Plan showing (on a basis that is not formally binding) the evolution of the public finances.
Timeliness:
The annual budget must be enacted before the start of the financial year.
Financial sufficiency and necessity:
Funds should be budgeted in sufficient amount –
but no more – to cover statutory purposes and other requirements of the budget period. 
“Packaging prohibition”:
The budget act may not deal with matters unrelated to the
annual budget.
Efficiency and economy:
Funds must be allocated and used having regard to these
complementary principles, which deal respectively with the achievement of optimal results
with allocated resources, and the reduction in resource utilisation in achieving results.
Budgetary balance:
The recent debt brake rule (see Section 2.1) re-casts and strengthens
the former budgetary principle about maintaining a broad balance between expenditure
and revenues. From this fundamental constitutional imperative, ancillary principles
regarding the 
accuracy and reliability
of the budget data, which are the key tools of fiscal
management, might reasonably be inferred.
Democratic authorisation and accountability:
The parliament (in particular the
Bundestag
or lower house) has full power to authorise and amend the budget, and to receive
audited accounts of its implementation.

---

BUDGET REVIEW: GERMANY
OECD JOURNAL ON BUDGETING – VOLUME 2014/2 © OECD 2015