One of the goals of the Widening and Outreach Pillar is to broaden CESSDA's European coverage. Support for building mature data services is key for countries to become a member of CESSDA.

The Mentorship Programme offers one-to-one support to aspiring member service providers. It matches interested prospective non-members, or new and immature service providers, with experts active in the Mentorship Programme. The purpose is to help the mentees define and realise their short-term goals. These can be strategic, policy-related, practical, or technical.

Interested candidate service providers can apply to join the programme. Their proposal should include information on the current situation at the archive and on their goals for building and developing their services in the years to come. They should explain how CESSDA experts can help them achieve their goals and what they intend to gain from the mentorship programme.

In 2021-2022, the programme involved six mentors - ADP, AUSSDA, CSDA, FORS, SND and TARKI - providing support to six mentees: DASS BiH (BA), LiDA (LT), SASD (SK), DASSI (IT), DATICE (IS), and LSSDA (LV).