Zeller, a Melbourne-based fintech founded by former Square executives to serve small- to mid-sized businesses, has raised $50 million AUD (about $37.5 million USD) led by Spark Capital, the investment firm whose portfolio also includes Twitter, Slack and Coinbase. Zeller’s valuation is now $400 million AUD (about $301 million USD).

The funding included participation from returning investors Square Peg, Apex Capital Partners and Addition, and brings Zeller’s total raised in less than a year to $81 million AUD. This amount includes a pre-launch Series A led by Addition, the investment firm started by Lee Fixel, and seed funding.