[hollerith]

A single transaction can contain multiple "transfers", so this next should handle your example. (I don't know the name of any organizations that collect VAT, so I used "vat-authority".)

    transfers:
      - from: robert-q-customer
        to: john:cash
        amount: 1000 usd
      - from: john:payable
        to: vat-authority
        amount: 200 usd