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 are issuing a credit note and hoping the customer does not notice before you catch it yourself.
The usual next step is a dedicated billing platform. That fixes the manual work, but creates a different problem. Most billing tools want to own your invoicing, because that is 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 does not replace Xero invoicing, 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 exactly what it has always been for your business: the source of truth.
Why this matters for SaaS specifically
Subscription billing has its own quirks that generic invoicing tools do not handle well:
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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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Day-accurate proration when a customer adds seats, upgrades, or downgrades mid-cycle.
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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, removing the risk of double-billing 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 are spending your evenings raising invoices by hand or untangling proration that should take thirty seconds, 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 customer 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. They appear in your Xero invoicing screen exactly as if you'd raised them yourself, with the correct contact, line items, amounts, and due dates already filled in.
How the automation works day to day
Once you've set up a subscription and attached it to a customer, Saasybill tracks the billing cycle in the background. When a renewal is due, Saasybill automatically generates the invoice in Xero on the correct date, using the pricing and plan structure you configured. If a customer changes their subscription mid-cycle, whether that's adding seats, upgrading a tier, or downgrading, Saasybill calculates the exact prorated amount based on the number of days remaining in the current billing period and reflects that on the next invoice. Every invoice raised carries a revenue classification of New, Renewal, or Expansion, applied automatically, so your Xero reporting can distinguish between a fresh sale and organic growth from existing customers without any manual tagging.
Setup Mode for a safe migration
If you're moving from manual invoicing, spreadsheets, or another billing tool, the integration includes Setup Mode. This lets you build out your subscriptions and pricing in Saasybill first, mirroring where each customer currently sits in their billing cycle, before switching automation on. That means your first live invoice from Saasybill picks up exactly where your manual process left off, with no duplicate charges and no missed renewals during the transition.
Reporting and reconciliation
Because Saasybill never routes revenue through a separate ledger, there is no reconciliation step between Saasybill and Xero. Xero's own reporting, including profit and loss, aged receivables, and revenue by contact, reflects your subscription revenue in real time, exactly as it would if you'd created every invoice manually. Your accountant or bookkeeper doesn't need access to Saasybill, doesn't need training on a new platform, and doesn't need to adjust how they work with your Xero file at all.
Ongoing sync
The connection between Saasybill and Xero remains live for as long as the app is connected. Contact updates, new customers, and subscription changes are reflected in the next invoice run without any manual re-sync required. If you ever disconnect Saasybill, every invoice it has already created in Xero remains exactly where it is.
Pricing plans
This app includes a free 14 day trial
Traction
- Revenue Dashboard
- Automated Billing
- Multiple Plan Types
- Prorated Billing Items
- Xero Integration
Scale
- Revenue Dashboard
- Automated Billing
- Multiple Plan Types
- Prorated Billing Items
- Xero Integration
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. You can set up as many plans as you need, and 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. If you have several pricing models, set up your most common one first, 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, and every question is answered by someone who actually built and understands the product, not a support queue reading from a script.
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.
