Disclosure: I work at Bento for Business.

Sounds like a perfect use case for our virtual cards!

Our API lets you create virtual cards with custom controls (max dollar amount, days active, category, card on/off) from a bank account that can be funded via ACH. Although the money is kept in a central deposit for your business, each card can have part of the money allocated for purchases and be controlled with our API (https://apidocs.bentoforbusiness.com/). This allows you to easily track expenses at an individual card level.

Let me know if you have any questions. You can reach me @ api-support@bentoforbusiness.com.