You're right to consider this, as it's an important aspect from a legal perspective.
Since Small Transfers doesn't store customers' funds or allow them to withdraw a balance, the platform is not considered an e-money institution or a "wallet".
When the customers pay their balance, we immediately forward the funds to the merchants.
Ultimately, the merchant bears the risk of non-payment, but the platform does its best, using industry-standard practices, to pre-check the customer and their payment methods for fraud and ensure a successful payment.
If a merchant successfully authorizes a charge, the amount is reserved for that merchant for a limited period. Trying to capture that amount (or less) during this period will succeed.
Yes, Small Transfers is the merchant of record for the card charge. We transfer only funds actually received to the merchant's Stripe account; we don't advance funds. As per the Terms (§1 "Transfer" and §5.6 "Non-Payment"), chargebacks/reversals are net-deducted from future transfers, so the seller bears non-payment risk.
Details: https://smalltransfers.com/terms
What happens when customers don't pay their balance?
What happens when the charge attempt fails after initial preauth?