If your agency collects recurring retainers on credit cards, you are donating a real slice of your margin to processing fees every month. Here is the math and the fix.
The fee math on a typical retainer
Card processing runs roughly 2.9% + $0.30 per charge. On a $2,000 monthly retainer that is about $58 per client, per month — roughly $700 a year, per client. Across a 20-client book, that is real money you are not getting back.
ACH via bank-link changes the math
ACH via bank-link (using a broker like Plaid) lets the client authorize payment from their bank account by signing into their bank — no typing account numbers. On platforms like Stripe, ACH is typically 0.8% capped around $5. That same $2,000 retainer costs about $5 instead of $58. ACH takes one to three business days to clear, which is fine for scheduled retainers.
When card still wins
Keep cards for small one-time charges, anything where speed matters, and clients who simply prefer card rewards. The rule of thumb: recurring B2B retainers belong on ACH; small or urgent charges stay on card.
How to switch clients over
Don’t force it — offer it. When a retainer renews, present ACH as the default with card as the backup. Most clients don’t care which rail they pay on; they care that it’s easy and secure. Bank-link makes it both.
Handle failures gracefully
ACH failures (insufficient or uncollected funds) are different from card declines. A billing system with automatic retries and a friendly fail notice recovers most failed ACH charges within a week — without you chasing anyone. This is built into ACH bank-link billing in HubWho for Vendasta-reseller agencies.