CereTax for Rillet: Real-Time Sales Tax and VAT on Every Rillet Invoice

Published September 16, 2026

CereTax for Rillet is live. Companies that run their general ledger in Rillet can now calculate accurate, audit-ready sales tax or VAT on every invoice and credit memo in real time, with the tax lines written back into Rillet before the invoice goes out.

Why This Matters

Rillet is the accounting platform for finance teams that closed the books in days and want to close them in hours. Revenue recognition, consolidation, and the close itself run inside one system. Tax has usually been the exception: calculated somewhere else, pasted in, and reconciled at month end by whoever owns the spreadsheet.

Every one of those manual steps is a place for the number to drift. A rate expires. A new state starts taxing software. A credit memo reverses an invoice at today's rate instead of the rate that applied when the invoice was issued. None of these show up until an auditor, a customer, or a controller finds them.

CereTax for Rillet puts the calculation inside the invoice event. The tax on the invoice in Rillet is the tax CereTax calculated for that customer, that product, and that address, at that moment.

What You Get

• Tax on every invoice event. Rillet sends a webhook when an invoice or credit memo is created, updated, or paid. CereTax calculates the tax and writes the result back to the document. One-time and recurring invoices take the same path.
• Sales tax or VAT, detected automatically. The connector reads the tax type on the Rillet document and routes it to sales tax or VAT calculation. Domestic and international invoices run through the same setup with no per-invoice configuration.
• Tax codes per product. Sync your product list from Rillet, assign a CereTax product and service code to each item one at a time or by spreadsheet import, and set a default for anything unmapped. Product-level codes are what separate a taxable subscription from an exempt professional service on the same invoice.
• Jurisdiction-level detail, or one line. Choose detailed output and each invoice carries one tax line per jurisdiction. Choose summarized output and it carries a single tax line. Either way the full calculation record stays in CereTax for audit.
• Credit memos reverse against the right period. When a credit memo links to an original invoice, the connector uses the original invoice date on the reversal, so the credit files against the period the tax was collected in. Partial credits carry their line amounts as issued.
• Tax-inclusive pricing. If your prices include tax, turn on tax-inclusive mode and CereTax backs the tax out of each line instead of adding it on top.
• Duplicate protection. If Rillet delivers the same webhook twice, or a user edits an invoice several times in quick succession, the connector processes the event once. No double-calculated tax.
• A log for every call. The connector's log tab records the CereTax request, the CereTax response, the Rillet update, and any error, searchable by Rillet invoice ID.

How Setup Works

Setup runs through two admin screens and takes no code. Create an API key in Rillet, log in to the CereTax connector with your CereTax Portal credentials, enter both keys, set your defaults and ship-from address, and paste the connector's webhook URL into Rillet's webhook settings for invoices and credit memos. Rillet's sandbox pairs with the CereTax Cert environment and Rillet production pairs with CereTax production, so you can test before a live invoice sees a rate. Invoices post to CereTax as quotes when created and as posted transactions when paid, which keeps your CereTax reporting tied to cash.

Built on the Engine Behind 200+ Customers

This is the same CereTax platform that more than 200 companies rely on across software, manufacturing, retail, ecommerce, energy, and more. CereTax integrates with platforms that move more than $4 trillion in transactions each year, and Rillet is now on that list.

The engine behind the connector maintains 98k+ active tax rates, 67M+ taxability decisions, and 5.9M exemption decisions, researched and kept current by our in-house tax team. Every one of them is available on a Rillet invoice through a product and service code. When your catalog grows past a single subscription, into usage-based fees, bundled services, digital goods, and products that one state taxes and the next does not, the calculation already knows what to do. Behind it all sits rooftop-level precision and real people who answer the phone when you call.

Get Started

If your team closes in Rillet and still fixes tax after the invoice goes out, we should talk. Request a demo to talk to a sales tax expert.