Here are some opportunities for funding for (collaborative) workshop attendance.
Europe:
European Mathematical Society: Travel Grants
EMS Committee for European Solidarity will undertake actions to foster the development of mathematics in economically less-favoured regions within the geographical area of EMS membership. For this purpose and among other initiatives, the Committee awards travel grants to young mathematicians for presenting results at conferences or attending courses, or for research stays in foreign countries, normally up to a maximum of 900 euros in each case or 500 euros for trips within Europe.
Annual Deadlines: End of March and End of September
European Women in Mathematics: Travel Grants
EWM members and are at an early stage of their career or work in a developing country, who need funding (travel and/or accommodation, up to 400 EUR) for participating and giving a talk at a significant conference in their field.
Annual Deadlines: June 1 and December 1
UK:
London Mathematical Society: Early Career Travel Grants
The applicant should be an Early Career Researcher in mathematics, based in the UK. An Early Career Researcher is defined as a Master’s student, PhD/research student or anyone who has completed their PhD in the last five years (excluding academic career breaks). The scheme is open to both members and non-members of the LMS. Non-members must have their application countersigned by a member of the society.
Annual Deadlines: End of February and End of October
London Mathematical Society: Caring Supplementary Grants
To enable parents and carers to attend conferences and other research schools, meetings or visits by making a supplementary contribution towards caring costs. Any mathematician in the UK is eligible to apply for a grant. If the applicant is not a member then the application must be countersigned by an LMS member.
Several deadlines throughout the year, check site
USA:
American Mathematical Society/ Simons Foundation: Travel Grants
Individuals must have earned a PhD degree (or its equivalent) within four years of the grant start date in order to be eligible. Applicants must be employed by U.S. institutions, have U.S. home addresses, or be U.S. citizens working abroad. The applicant’s research must be in an area supported by the Division of Mathematical Sciences of the National Science Foundation.
Annual Application Period: February – March
Association for Women in Mathematics: Mathematics Travel Grants
Applicants must be women holding a doctorate (or equivalent) and with a work address in the USA (or home address, in the case of unemployed applicants). Anyone who has been awarded an AWM-NSF travel grant in the past two years is ineligible. Anyone receiving more than $2000 yearly in external governmental funding for travel is ineligible. Partial travel support from the applicant’s institution or from a non-governmental agency does not, however, make the applicant ineligible.
Annual Deadlines: February 1, May 1, and October 1
Association for Women in Mathematics: Mathematics Mentoring Travel Grants
Applicants must be women holding a doctorate or equivalent and with a work address in the USA (or home address if unemployed). The applicant’s research must be in an area supported by DMS.
Annual Deadline: February 1
International:
Sigma Xi: Grants-in-Aid of Research
US Citizenship and residence not required. International applications are welcome. Only undergraduate and graduate students currently enrolled in degree seeking programs may apply.
Annual Deadlines: March 15 and October 1
Elsevier: Mathematical Sciences Sponsorship Fund
This is an annual sponsorship, whereby an application needs to fall into at least one of three categories, which includes “Young researchers – travel grants for conferences or workshops”
Annual Deadlines: To Be Announced
The Kovalevskaia Fund
At present the main projects of the Fund are in Vietnam, Peru, Mexico, Cuba, and southern Africa.
May have to check site periodically for updates