financial sponsor; financial supporter
Primarily used in visa and immigration contexts to refer to the person or entity covering an applicant's expenses.
A certificate from the financial sponsor is required for the student visa application.
If the financial supporter is not a relative, additional documents may be required.
保証人 is a guarantor who assumes legal responsibility, while 経費支弁者 specifically provides financial support, often without the same legal liability.
スポンサー is a broader term for any sponsor (commercial, event, etc.), whereas 経費支弁者 is a formal term limited to financial support in official procedures like visa applications.
Compound of 経費 (expenses), 支弁 (payment, defrayal), and 者 (person). The term is a modern legal/administrative coinage.