No matter what the model of EMB used, budgetary restrictions provide an overall constraint on the number and types of positions that an EMB can afford to fund. EMBs following the Independent Model who have powers to hire and fire their staff may be best placed to determine their own structure. Even in such cases, the law or government regulation may have already determined key elements of the organisational structure, such as senior executive positions and required functional divisions.

All EMBs that rely on public service staffing for their secretariat may face constraints on their flexibility to determine their organisational structure. General laws and practices for the public service may require approval for all organisational structures from a central supervisory body, or set rigid standards for how departments, sections, subsections, and other work units must be structured. General laws and practices may also place restrictions on the use of non-public service contractors or experts. Governmental Model and Mixed Model EMBs, all or most of whose staff work within public service departments, may have even greater constraints, as their staff may have to fit not only the structure of a temporary electoral organisation structure but also the continuing work structure for their department or authority’s other tasks.

"Developing" is a key term for EMB organisational structures. Devising an initial structure is the first step, but maintaining an organisational structure that continues to meet the evolving legal framework, the rapid advances in electoral, information and communications technology, and the expectations of stakeholders, is a real challenge. Flexibility to meet these demands is more difficult when the organisational structure is partially or wholly defined by law or regulations of bodies other than the EMB, or where the EMB’s structure and staffing are subject to general public service rules. While constant organisational change is unsettling, inclusion of structural reviews in evaluations after major electoral events, and the EMB having powers to make changes or additions to organisational structures, can enhance the effectiveness of electoral management. Independent Model EMBs which have control of their own staffing may be better placed to have structural flexibility.