Overview
If you run a subscription-based SaaS business on Xero, you already know the problem. Manual invoicing works fine with a handful of customers. Somewhere around the 20 to 30 customer mark, it stops. Renewal dates slip through the cracks, and an upgrade mid-cycle means proration math done by hand on a Tuesday night. An invoice goes out wrong, and now you're issuing a credit note.
The usual next step is a dedicated billing platform. That fixes the manual work, but most billing tools want to own your invoicing, because that's how they make money: a transaction fee on everything that runs through their system. Your revenue data ends up in two places, and your accountant has to work around incomplete data pushed back into Xero.
Saasybill takes a different approach. It doesn't try to replace Xero invoicing, instead it automates it. You define your pricing, attach subscriptions to your Xero contacts, and Saasybill generates invoices automatically, at the right time, directly in Xero. Every invoice is a native Xero invoice, not a copy synced from a third-party ledger, so nothing needs reconciling between two systems. Xero stays the source of truth.
Why this matters for SaaS specifically
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Flexible plan structures: flat fee, per unit, tiered, volume, and stairstep, so you are not forced to simplify your pricing to fit the tool.
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Usage-based billing: meter usage and bill it in arrears, alone or on top of a base fee.
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Day-accurate proration when a customer adds seats, upgrades, or downgrades mid-cycle.
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Automatic CPI adjustments: annual subscriptions rise at renewal by the change in your country's CPI.
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Deferred revenue: annual invoices are held as a liability and released to revenue by the day, with the journals automatically posted to Xero.
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A public API and webhooks, so a signup or seat change in your product updates the subscription automatically.
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Automatic revenue classification as New, Renewal, or Expansion, so your reporting reflects what is driving growth.
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Setup Mode, so you can mirror your existing billing state before going live and never double-bill a customer during migration.
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Multi-currency billing and multi-user access, so Saasybill scales with the business as it grows
Who it's built for
Founders and finance teams at small to mid-sized B2B SaaS companies already using Xero for accounting, past the point where manual invoicing makes sense and ready for it to run itself.
What you get
No transaction fees, ever. Saasybill charges a flat subscription, so what your customers pay you is what you keep. Invoices look like the ones you would raise yourself, because they are created directly in Xero, so your accountant needs no onboarding or new software. Setup is simple enough to run yourself: connect Xero, define your pricing, attach it to your customers, and you are live.
If you're spending your evenings raising invoices by hand, Saasybill gives you that time back.
Saasybill + Xero
Saasybill connects to Xero through the official Xero API.
Once connected, Saasybill reads your existing Xero contacts so you can attach subscriptions to customers you already have on file, with no need to re-enter details. From there, Saasybill creates invoices directly in Xero. These are standard, native Xero invoices, not a copy or a summary pushed in from elsewhere, with the correct contact, line items, amounts, and due dates already filled in.
How the automation works
When a renewal is due, Saasybill generates the invoice in Xero on the correct date, using the pricing you configured. If a customer adds seats, upgrades, or downgrades mid-cycle, Saasybill prorates to the day and reflects it on the next invoice. Every invoice is classified as New, Renewal, or Expansion automatically, so your Xero reporting separates a fresh sale from growth in existing customers.
Usage-based billing
Report usage against meters such as API calls or messages. Saasybill prices it at the end of each period (per unit, tiered, volume, or stairstep, with included units) and adds it to the customer's next Xero invoice.
Automatic CPI adjustments
Annual subscriptions rise at each renewal by the change in the consumer price index over the previous interval. The increase is fixed on the renewal invoice in Xero.
Deferred revenue
Annual invoices are coded to a liability account you choose in Xero, and Saasybill posts a monthly journal that releases each line to revenue by the day. Voids and credit notes are reversed for you. This needs a connected Xero user with the Financial Adviser role.
The Saasybill API
A REST API with webhooks and a test sandbox that connects to a Xero Demo Company lets your own platform create subscriptions, change seats, and report usage. Each change still ends as a native Xero invoice.
Setup Mode
Moving from spreadsheets or another tool? Mirror each customer's current billing position in Saasybill before switching automation on, so your first live invoice picks up where your manual process left off, with no duplicate charges.
Reporting and ongoing sync
Saasybill never routes revenue through a separate ledger, so there is nothing to reconcile. Xero's profit and loss, aged receivables, and revenue by contact reflect your subscription revenue as if you had raised every invoice by hand. The connection stays live while the app is connected, so contact updates and subscription changes flow into the next invoice run. If you disconnect, every invoice already created stays in Xero.
Pricing plans
This app includes a free 14 day trial
Starter
- Xero integration
- Revenue dashboard
- Automated billing
- 5 plan types
- Prorated billing items
- Quote calculator
- No transaction fees
- Up to 25 subscriptions
- Up to 2 users
- One currency
- Limited AI reports
Traction
- Finance Pack $20.00 /month
- Developer Pack $20.00 /month
- Xero integration
- Revenue dashboard
- Automated billing
- 5 plan types
- Prorated billing items
- Quote calculator
- No transaction fees
- Up to 100 subscriptions
- Up to 5 users
- Multiple currencies
- AI reports
- Finance & Developer Packs available
Scale
- Finance Pack $20.00 /month
- Developer Pack $20.00 /month
- Xero integration
- Revenue dashboard
- Automated billing
- 5 plan types
- Prorated billing items
- Quote calculator
- No transaction fees
- Up to 250 subscriptions
- Up to 10 users
- Multiple currencies
- Larger AI reports allowance
- Finance & Developer Packs available
Getting started
Getting your first automated invoice running takes just a few minutes and looks like this:
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Connect Xero. Click "Get this app" and authorise the connection using your existing Xero login.
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Set up your pricing. Define your plans in Saasybill: flat fee, per unit, tiered, volume, or stairstep, whichever matches how you actually charge. Add new ones later as your pricing evolves.
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Attach subscriptions to customers. Pick from your existing Xero contacts and attach the relevant plan and billing cycle. No need to re-enter customer details that are already sitting in Xero.
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Use Setup Mode if you're migrating. If you're moving off manual invoicing, a spreadsheet, or another billing platform, Setup Mode lets you mirror each customer's current billing position before anything goes live. This removes the risk of double-billing someone during the switch.
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Go live. Once your pricing and subscriptions are set up, Saasybill takes over the invoicing. Renewals are raised automatically, mid-cycle changes are prorated to the day, and every invoice appears directly in Xero, ready to send.
Tips for a smooth setup
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Start with your simplest plan first. Set up your most common pricing model, confirm the first invoice looks right, then add the rest.
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Use Setup Mode even if you think you don't need it. It costs a few minutes and removes any risk of a customer being billed twice during the transition.
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Check your Xero contact details. Saasybill pulls contact and invoicing details straight from Xero, so accurate contact records mean accurate invoices from day one.
Support and trust
Saasybill is built specifically for small to mid-sized SaaS businesses on Xero, so setup is designed to be handled by the person running the business, not a technical team. If you get stuck at any point, support is available directly through Saasybill.
Because every invoice Saasybill creates lives natively in Xero, there's no risk of losing your billing history or being locked into a system that holds your revenue data hostage. If you ever decide Saasybill isn't the right fit, every invoice it has raised stays exactly where it is, in Xero, where it always belonged.
Reviews & ratings
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Most recent reviews
Makes subscription billing easy
Response from Saasybill
Time saving and simple
Response from Saasybill
Keeps our books incredibly clean and saves us a tonne of time
Response from Saasybill