How it works

From plan setup to Xero invoice, automatically.

A complete walkthrough of how Saasybill handles subscription billing. Every step from first setup through to renewals, mid-cycle changes, and proration.

The billing lifecycle

Six steps from setup to running on autopilot.

Walk through each stage of a subscription. Click any step to see what Saasybill does and why it matters.

Step 1 of 6

Create a plan

Plans are the foundation of every subscription in Saasybill. You choose a billing model, set the renewal period, and define what the unit represents for your business. Plans can sit in draft while you configure them and go active when ready.

Choose from five models: Flat Fee, Per Unit, Tiered, Volume, or Stairstep.
Set the period to monthly or annual renewal.
Name units to match your business: seats, users, licences, or anything else.
Detail: Categories let you group plans for reporting. A plan can be reused across many customers, each with their own subscription and billing cycle.

Proration

What happens when a plan changes mid-cycle.

When a subscription changes part-way through a billing period, Saasybill works out the value of each plan for the remaining days and charges the difference. If the new plan costs more, that difference is invoiced. The maths uses the exact effective date of the change, not an estimate or a monthly average.

The effective date does not have to be today. If a customer agreed to upgrade last week but you are entering it now, you can backdate the change and the proration will reflect the actual date the new plan took effect. Equally, if a change is agreed in advance, you can forward-date it and Saasybill will apply the adjustment from the correct point in the period.

Once calculated, the adjustment can be charged immediately as a new invoice or rolled into the next renewal, depending on how the change is configured.

Charge immediately
A new invoice is generated for the prorated difference on the day of the change.
Charge on renewal
The difference is calculated now but added to the next renewal invoice instead.
The worked example shows a customer upgrading from $120/month to $240/month with 15 days remaining. Saasybill values each plan for those 15 days and invoices the $60 difference.

Worked example: upgrade mid-cycle

Current plan$120 / month
Upgraded to$240 / month
Change dateDay 15 of 30
Days remaining15
Old plan value for 15 days
15 ÷ 30 × $120
$60
New plan value for 15 days
15 ÷ 30 × $240
$120
Difference charged$60

This $60 can be charged as a new invoice immediately, or added to the next renewal. Configured per subscription.

Next renewal

Full month at new rate$240

See it with your own billing workflow.

Start a free trial and have your first subscription running in minutes. Or request a demo and we will walk through it with your Xero setup.