According to SEC filings, PLASTIQ has raised $2.35M in venture financing. 16 separate investors participated in the offering.

From the firm's website:
PLASTIQ ("PLA-stick") makes payments possible, but we are not about payments. We are about payers - the people behind the payment. Yep - that's you! Why do we care about you? (wow, doesn't that sound nice?) Because, well, we know others don't or can't or at least pretend to but don't really mean it. So we said "here's a new, exciting option to pay for anything and everything "big" in your life - convenient, a la carte, fun, rewarding, and secure.

But most of all, we've got some long term tricks up our sleeves. To us, the payer - you - represents a set of beliefs and values that we strive to understand and match over time. PLASTIQ seeks to make possible those connections to what you care about most - from education to travel, charity to church, music to the fine arts, or simply kicking back and enjoying that "free time" which, in today's world, doesn't always seem without cost.