Aquadratic vs Polar

Aquadratic is a merchant of record for selling digital products. It handles payment, product delivery, tax compliance, fraud protection, and payouts for independent creators, developers, and digital product suppliers. Sellers can provide a hosted checkout, an embeddable widget, or REST API access. After payment, the service can email license keys and digital products. Listed payment methods include cards through Stripe, PayPal, and cryptocurrency; named processing integrations are Stripe, PayPal, and NOWPayments. Aquadratic says it calculates, collects, and files sales tax and VAT worldwide, and manages disputes and chargebacks. The core platform has no monthly fee and costs nothing, billed at 7% per transaction; processor fees may apply. AquaDrop Starter is free, while AquaDrop Pro is $19 a month and AquaDrop Scale is $49 a month. Aquadratic says payment data is primarily handled by processors, and that it does not store complete card numbers. Its support response time is 24–48 business hours.

Polar is a billing stack for AI products, combining subscriptions, usage billing, credits, invoicing, and merchant-of-record services. It collects usage events into customer meters and adds metered charges to the next invoice. Meters can count, sum, average, find minimums or maximums, and track unique values. Usage collection options cover LLM activity, streaming responses, S3-compatible storage, elapsed time, and manually submitted events; LLM integrations include the Vercel AI SDK and compatible models that return usage data. As merchant of record, Polar says it resells products in over 100 markets and handles payments, sales tax, fraud, refunds, and chargebacks. Its hosted checkout supports localized currencies and includes sales tax. Automated benefits include usage credits, license keys, file downloads up to 10GB, and invitations to private GitHub repositories and Discord. Polar lists apps for iOS and Android and plugins for Raycast and Framer. The Starter plan is free; Pro is $20/month, Growth is $100/month, and Scale is $400/month, with transaction fees on each plan. Usage meters do not block activity when a quota is exceeded; the product using Polar must enforce limits.