A Bizarre Dispute Over Union54’s Origins Is Threatening ChitChat’s Future

A bitter dispute over the origins of Union54, the Zambian fintech that made waves as the first African card-issuing API startup accepted into Y Combinator, has erupted into the open, threatening to overshadow its reinvention as ChitChat.

On September 9, 2025, Zambian tech entrepreneur Patrick Sikalinda filed a lawsuit in the country’s High Court alleging that he co-founded Union54, held a 33 percent equity stake, and was removed from the company without his consent or compensation.

The company, now operating as ChitChat, disputes this. In a letter from its legal counsel dated June 26, 2025, the company described Sikalinda as a short-term subcontractor who never held equity, never signed any shareholder agreements, and was removed for non-performance. The case sets up a high-stakes fight over ownership of what was once one of the continent’s most closely watched startups.

From Zazu to YC

Union54’s roots lie in Zazu, a digital banking venture previously led by Union54 CEO Perseus Mlambo. Zazu had secured access to Mastercard rails via a partner called Paymentology, and its existing infrastructure became the foundation for what became Union54.

In early 2021, Union54 applied to Y Combinator. According to Sikalinda, he and Mlambo jointly prepared the pitch, product demo and technical documentation. He says he was listed as a co-founder holding 33 percent equity on the YC application form, a claim he says is supported by WhatsApp exchanges in which Mlambo instructed him to enter that figure, which he showed to WT.