Sequential Flows

Sequential Flows let you automatically modify a customer's subscription at specific order milestones — no manual work required. You define rules like "after the 3rd order, do X" and Zubs takes care of the rest on every billing cycle.

What you can do

Each flow is tied to a subscription plan and consists of one or more rules. Each rule triggers on a specific order number and can perform the following actions:

• Replace a product — Swap one variant for another (e.g. upgrade a customer to a larger size after their 2nd order)
• Apply a discount — Set a percentage or fixed discount on a line item (e.g. give 10% off after the 4th order)
• Add a free one-time item — Include a bonus product in the next order at no charge (e.g. send a free sample after the 2nd order)

How order counting works

Rules are worded as "after the Nth order", and Zubs counts orders from the very start of the subscription:

• The 1st order is the order the customer places when they subscribe — their checkout order.
• The 2nd order is their first renewal, the 3rd order the second renewal, and so on.

So "after the 1st order" means after the checkout order, and "after the 2nd order" means after the first recurring order.

When the action is applied

A sequential flow runs the moment its order number is created — it's triggered by that order, not queued for just before the next one. So "after the Nth order" means Zubs reacts as soon as order N exists and immediately updates the subscription, which is why the change is prepared far ahead of order N + 1 rather than at the last second before it bills. The order that triggered the flow is already placed and is never touched — the change first appears on order N + 1:

• "After the 1st order" fires as soon as the checkout order is created, then applies to the customer's next order (their first renewal) — the checkout order itself is never modified.
• "After the 3rd order" fires when the 3rd order is created and first takes effect on the 4th order.

Because the flow runs right when order N is created, that first affected order (N + 1) is prepared immediately and shows the Scheduled change badge well before it bills (see Where scheduled changes appear). What happens over the following orders depends on the action:

• Replace a product and Apply a discount modify the subscription itself, so the change stays on every order from that point onward.
• Add a free one-time item is added only to that next order — it's a one-off, not recurring.

Each rule fires once, right after its order number; it isn't re-evaluated on later orders. To keep an effect running past a milestone, use a persistent action (replace or discount) rather than the one-time free item.

Subscriptions a flow leaves alone

A flow only changes a subscription where one payment covers exactly one delivery. On a prepaid subscription — one payment covering several deliveries — the rules are skipped, and the subscription's timeline records the action as skipped rather than applied. One payment has already covered those deliveries, so what they contain and what they cost are both fixed — the same reason items and frequency can't be edited there.

The same goes for the handful of plans whose billing cycle doesn't cover a whole number of deliveries — weekly deliveries billed monthly, for example, where the number of deliveries per charge varies from one cycle to the next. Zubs can't work out what a replaced product or a discount should cost per charge there, so it leaves the subscription alone rather than charge the wrong amount.

If you want a milestone change on one of these subscriptions, cancel it and create a new one on the schedule the customer wants.

Example use cases

Loyalty discount at milestone Offer a 15% discount after the 3rd order to reward long-term subscribers and reduce churn.

Automatic product upgrade Start customers on a starter pack, then automatically replace it with the full-size version after the 1st order.

Win-back before likely cancellation Apply a discount after the 5th order — a common point where subscribers reconsider — to keep them around.

Surprise gift for loyal subscribers Add a free one-time item after the 6th order as an unexpected thank-you — a small gesture that delights customers and strengthens retention.

How to create a flow

1. Navigate to Sequential flows in the sidebar
2. Click Create flow and give it a name
3. Select the subscription plan(s) the flow applies to
4. Add a rule with a trigger order number and an action
5. Save and activate the flow

Flows only apply to new orders going forward from the point they are activated.

Where scheduled changes appear

Once a flow will affect an upcoming order, that order is previewed with the change already applied — before it actually bills:

• Customers see a Scheduled change badge on the affected order in their upcoming orders view, with a short note (e.g. "From this order on, the price of your subscription changes") and the new price shown next to the old one.
• You see the same badge on that order in the contract's upcoming billing cycles in the merchant portal, noting which flow applies and after which order.

The preview is informational — the change is applied automatically when the order actually bills.

Subscriptions a flow leaves alone show no badge — there's nothing scheduled to change.