How to migrate your agency's client billing to your own merchant account
A step-by-step guide for marketing agencies that want to move end-client billing off a patchwork of QuickBooks, Stripe, and spreadsheets and onto their own Stripe Connect or Authorize.net merchant account — without disrupting fulfillment.
“The biggest mistake is migrating clients in random order. Always migrate the largest 20% of clients first — that's where the processing-margin savings land hardest.”
Why agencies consolidate in the first place
Most agencies start with whatever billing tool was already in front of them — a generic invoicing app, a card link, a spreadsheet to reconcile it all. For an agency under ~20 clients, that stack often works fine.
Two limits show up as you scale. First, payment processing fees stack up faster than you'd expect, and the markup is rarely a line item you can see. On a $400K/year card volume, moving to your own merchant and ACH typically recovers $4K–$12K of margin per year. Second, a patchwork billing stack doesn't surface per-client gross margin (your retail price minus your own wholesale/product cost). You can build it in a spreadsheet, but only after the month closes.
Consolidating onto your own merchant solves both. Stripe Connect makes the merchant onboarding live in hours. Authorize.net / NMI takes 2–5 business days for underwriting but gives you the lowest rates once approved.
The seven-step migration sequence
Step 1 — Pick a processor. Stripe Connect if you want to go live this afternoon; direct merchant via Authorize.net / NMI if you'd rather wait a week for underwriting and capture lower per-transaction rates. HubWho supports both, and you can run both in the same tenant — useful when you have a few enterprise accounts on direct and the long-tail on Stripe.
Step 2 — Set up your catalog and clients in HubWho. Add your products with the wholesale cost you enter and your retail price, then add your clients. A source-agnostic CSV importer is the fast on-ramp: export your client list and subscriptions from your current tool or spreadsheet and bring them across so you don't rebuild by hand. HubWho runs standalone — nothing changes in your old billing tool, and it keeps working until you switch each client over.
Step 3 — Audit the first 20% of clients. Sort your client list by monthly billing total, descending. Take the top 20%. These are where the migration math is most positive (highest dollar volume = highest absolute processing-margin savings).
Step 4 — Migrate one client end-to-end as a pilot. Pick a friendly account. Inside HubWho, create the subscription, set the price, send the first invoice (which goes through your merchant), confirm payment lands. This step is non-destructive — leave the client's billing in your old tool paused, not deleted.
Step 5 — Move the top 20% in a single batch. Once the pilot looks good, do the remaining priority accounts the same way. Two hours of focused work. Don't spread it across days — context-switching kills the pacing.
Step 6 — Long-tail in waves. The bottom 80% of clients can move in weekly batches. No rush — your old billing tool still works for any client you haven't migrated yet.
Step 7 — Turn off billing in the old tool per client only after the first HubWho payment settles. Until that payment lands, keep the old tool as the failsafe.
What can go wrong (and how to avoid it)
Client billing-day mismatch. If a client is on a 5th-of-the-month cycle in your old tool and you switch to HubWho's 1st-of-the-month cycle, they'll get two bills in the transition month. Solve this by setting the HubWho invoice date to one billing cycle later, or by sending a small credit memo to cover the overlap.
Missed Plaid setup. If you're switching the client from card to ACH at the same time, send a portal-access email with explicit instructions. About 30% of clients will set up Plaid same-day; the rest need a nudge. HubWho's portal handles both.
Cancelling the wrong thing upstream. If the service you fulfill is provisioned in a separate tool, only pause the billing — don't cancel the underlying subscription that controls provisioning, or you'll stop the service the client is paying for.
What you get on the other side
Per-client gross margin appears in HubWho on demand. Pull it any time and you'll see immediately which clients are profitable and which are loss-leaders.
Your processor margin is your processor margin — no mystery markup baked into rates.
Branded customer portal — your logo, colors, and business name. Clients pay, view invoices, see KPI snapshots — under your brand (custom-domain routing is rolling out; today the portal lives at app.hubwho.com/portal).
Dunning is being built to run per client — a gentle multi-step sequence for healthcare clients, a firmer sequence for chronic late-payers — instead of one one-size-fits-all reminder.