Responsibility for ensuring that necessary funding is in place to finance a TIWB programme resides with the Host Administration. Host Administrations may do so entirely through own internal resources or their donor network to fund the costs of a TIWB programme. This forms part of the Host Administration’s engagement and high-level commitment to the TIWB programme's objectives. The TIWB Secretariat is also able to assist in mobilising funding for all or part of a TIWB programme by drawing on its network of Partner Administrations and Donors.

The Host Administration should make best efforts to establish whether other government agencies (e.g. Ministry of Finance) or Donor Partners with whom the Host Administration is already working, may be able to partially or completely fund the proposed TIWB programme.

• Self-Funding: All TIWB programme costs are met by the Host Administration and/or host government.

• Donor Funding: The Host Administration provides partial (base) funding for the TIWB programme, e.g. the Expert's travel costs or daily expenses. This base funding is complemented by additional "top-up" funding by a Donor in order to meet the remaining programme costs. Often, the Donor is already involved in providing a broader programme of development assistance to the Host Administration (or its Ministry of Finance).

• Sponsored Secondments: If the Expert is an official currently on secondment from a Partner Administration, the costs of the TIWB programme may be partially or fully funded by the Partner Administration. For example, the Partner Administration may continue to pay the salary of the official, and may also cover the Expert's travel and daily expenses. Alternatively, the Host Administration or a Donor could meet the Expert's travel and daily expenses. Occasionally, the Partner country's governmental development agency, rather than the Partner Administration, will bear all or part of the programme costs.
• TIWB Funding: In the case where the Expert is an industry expert, a retired tax official, a currently serving official who has taken leave without pay from his or her full-time position, or a TIWB Roster Expert, the TIWB programme is financed through the UNDP-managed TIWB Fund.