Chargeback Specialist

About the team:

Sum Up's Disputes team sits at the heart of our financial integrity operations, protecting both our customers and the business from fraud and financial loss. As card transaction volumes grow rapidly across our 37 markets, so does the complexity and volume of disputes we handle — making this team's work more critical than ever. We're building out the team to meet strict PSD2 compliance requirements and ensure every customer who reports a dispute gets a fast, fair, and thorough resolution.

This role is a direct response to that growth: you'll join a team of specialists who are the last line of defence for cardholders facing fraud, unauthorised transactions, and unresolved payment issues, as well as for merchants disputing chargebacks raised against their businesses.

• Analyze and process dispute and chargeback claims from both cardholders (Issuing) and merchants (Acquiring), managing cases end-to-end in line with card scheme regulations via Salesforce.
• Handle fraud-related notifications and manage post-chargeback activities — including representments and pre-arbitration — with the relevant card schemes on both sides of a transaction.
• Protect customers and the business by applying the appropriate dispute processes for each case type, recovering funds and reducing financial exposure across Issuing and Acquiring portfolios.
• Keep up to date with AML, fraud prevention, and chargeback industry standards across both Issuing and Acquiring to ensure ongoing compliance.
• Communicate clearly with cardholders and merchants throughout the dispute resolution process, ensuring a consistent and positive experience regardless of the case type.
• Support internal and external partners by responding to information requests related to ongoing Issuing and Acquiring cases.

• You have experience working with payment systems, card transaction processes, or financial operations, with a solid understanding of how payments flow end-to-end — on both the issuing and acquiring side.
• You have strong attention to detail, with the ability to assess dispute cases carefully and apply the right fraud prevention or detection approach depending on whether the claim originates from a cardholder or a merchant.
• You're familiar with chargeback regulations, card scheme rules (Visa, Mastercard), or anti-fraud frameworks across Issuing and/or Acquiring — or have a genuine eagerness to build that knowledge quickly across both.
• You're comfortable navigating multiple back-office systems and platforms to gather information and reach accurate conclusions under time pressure, across different dispute workflows.
• You can communicate clearly and professionally with both customers and internal teams throughout complex case investigations, adapting your approach to the needs of cardholders and merchants alike.

• Opportunity to work with Sum Uppers globally on large-scale fintech products used by millions of businesses worldwide, from our modern Sofia office. This involves an office-first setup

• Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced

• A dedicated annual L&D budget of €2000 and 10 paid days of educational leave which can be used to attend conferences and/or advance your career through further education

• Generous time off: 25 days of paid leave, plus one extra day per year of service (up to 35), along with public holidays and special leave options

• Peace of mind: additional health insurance and life insurance

• Stay active:
  
  on-site yoga and a co-sponsored Multisport card offering access to hundreds of sports facilities

• Meal support: benefit from a tax-free food voucher program plus flexibility via our Re:
  
  Benefits platform

• Easy commute: free shuttle buses connecting directly to Joliot-Curie metro station

• Break4me: 1-month sabbatical after 3 years of service

• Referral Bonus: earn additional rewards by referring talented individuals to join the Sum Up team

Be empowered to do more that matters.

At Sum…