With the almost $4 billion acquisition of heavily backed US firm Melio Payments, Xero chief executive Sukhinder Singh Cassidy hopes to prove to shareholders in her company that she is worth her sky-high salary.

The $US2.5 billion ($3.9 billion) deal is Singh Cassidy’s biggest move since the New Zealand-founded company broke its mould when it hired the San Francisco-based executive in late 2022 to try to turn the accounting software star into a US-led fintech giant.