Indirect tax software should know where you owe, calculate it on every invoice, and file it
Tax engines differ in coverage, in how they connect to your billing and commerce systems, and in whether they file for you. Test with your own products and states.
Published 29 October 2026; vendor pages read 29 October 2026.
Choose tax compliance software by four tests: does it tell you where you have an obligation to register, does it calculate the right tax on your actual products in each place, does it file and remit (or only prepare), and does it connect to the systems that create your invoices. Indirect tax products range from calculation engines your developers call, to managed services that register, file and pay on your behalf.
This guide covers sales and use tax, VAT and GST, and the e-invoicing and reporting obligations that come with them. It is for controllers, tax managers and finance leads. It does not rank products; vendors are listed alphabetically below with the same facts for each, from their own pages.
Who needs this, and when
The usual triggers: sales into a new state or country, a registration you discover late, a product line whose taxability is unclear, exemption certificates held in email, or an e-invoicing mandate in a country where you sell. In the EU, the VAT in the Digital Age package lets member states introduce mandatory e-invoicing under specific conditions, and digital reporting requirements will affect cross-border B2B transactions from 1 July 2030 1.
Income tax and global minimum tax are separate problems. The EU has implemented Pillar 2 for large groups 2; that is a group reporting task, closer to the consolidation guide than to sales tax software.
Requirements checklist
Tax compliance: requirements
Must have: every product on your shortlist should do it. Depends on you: test it if your situation calls for it.
Must have
- Monitoring of where you have crossed a registration threshold, by state or country, from your own sales data.
- Calculation at the line level, using product tax codes you can see and change.
- Connections to every system that creates invoices or orders: billing, ERP, commerce, marketplaces.
- Returns prepared from the same transactions, with a reconciliation to your ledger.
- A record of every calculation and filing, kept and exportable.
Depends on you
- Filing and remittance on your behalf, if you want a managed service rather than software.
- Registration services, if you are entering new places.
- Exemption certificate collection and validation, if you sell to exempt buyers or resellers.
- E-invoicing and real-time reporting, if you sell in countries that require them.
Print this checklist to take into a demo.
If your situation is this, look for that
| If | Then |
|---|---|
| You sell software or digital services | Check how the product taxes SaaS and digital goods in each place you sell. |
| You sell through marketplaces and your own site | Ask how marketplace-collected tax is excluded from your returns. |
| You want filings off your desk entirely | Look at managed services that register, file and remit, and read what they guarantee. |
| You sell B2B in Europe | Look at VAT number validation, e-invoicing and the ViDA timeline 1. |
| You would rather not be the seller of record | Compare merchant of record models in the billing guide. |
What it costs: the components to ask about
| Component | What to ask | Where to find it |
|---|---|---|
| Subscription | Monthly or annual fee, often by revenue band, transaction volume or number of states. | Pricing page; several vendors here publish one. |
| Per filing | Price per return filed, per state or country, per period. | Pricing page. |
| Registration | One-time fee per registration. | Pricing page. |
| Calculation volume | Price per transaction or API call above an included volume. | Pricing page or order form. |
| Integrations | Fees for connectors to your billing, ERP or commerce systems. | Integrations page or order form. |
| Exit | Export of transactions, calculations, returns and certificates. | Master agreement. |
Implementation timeline
- Weeks 1 to 2: assess. Run nexus or threshold analysis on twelve months of sales data.
- Weeks 2 to 4: register. Register where needed; agree how prior-period exposure will be handled with your advisers.
- Weeks 3 to 6: map products. Assign tax codes to every product and service.
- Weeks 4 to 8: connect. Integrate billing, ERP and commerce; test calculations against known answers.
- First filing period: review. Check every return before it is filed and keep the confirmations.
Questions to ask in a demo
- Load our last twelve months of sales and show where we have crossed a threshold.
- Calculate tax on three of our products shipped to three places, and show the tax codes used.
- Which returns do you file and pay for us, and which do you only prepare?
- If a return you filed is wrong, what does the contract say you cover?
- Show an exemption certificate collected, validated and applied to an invoice.
- What do we export if we leave, and for how many years can we access it?
Red flags in a contract
- Coverage you cannot see. Ask for the list of states and countries covered for calculation and for filing, separately.
- No accuracy or penalty clause in a managed filing service.
- Records that do not leave with you. Records that support a return must be kept until its period of limitations runs out 3.
- Per-transaction pricing with no overage table. Model peak season volumes.
- No SOC 1 report. Tax calculations post to your ledger and feed financial reporting 4.
The vendors, A to Z
These 6 vendors offer products for this job, going by their own sites. Each is listed in alphabetical order with the same fields, every one taken from the vendor's own pages or from the SEC on the date shown. Inclusion is not a recommendation, and a vendor whose pages we could not read is left out until we can; the method page explains how vendors are included.
Avalara
Sales tax calculation, returns and exemption certificate software. Published plans start with a monthly figure per state.
- In its own words
Automate your sales tax compliance with Avalara.
(avalara.com, read 29 October 2026)- Lists on its site
- AvaTax; Returns (avalara.com)
- Pricing
- The pricing page states
Sales tax and returns plans starting at $69/mo
(avalara.com pricing, read 29 October 2026) - Integrations it names
- Shopify; Microsoft; NetSuite; QuickBooks; Sage; Salesforce (avalara.com pricing)
- Public company
- No company named “Avalara” in the SEC's list of companies with tickers, read 29 October 2026. A listing elsewhere, or a parent company, is not checked here.
Fonoa
Indirect tax software for tax ID validation, calculation, e-invoicing and returns. No price list was found on the pages read.
- In its own words
AI platform for global indirect tax
(fonoa.com, read 29 October 2026)- Lists on its site
- Validate; Tax Engine; E-Invoicing; Returns (fonoa.com)
- Pricing
- Not published on the pages we read, 29 October 2026. Ask for a quote.
- Integrations it names
- No integrations taken from the pages we read.
- Public company
- No company named “Fonoa” in the SEC's list of companies with tickers, read 29 October 2026. A listing elsewhere, or a parent company, is not checked here.
Numeral
A managed sales tax, VAT and GST service with registrations and filings done for the customer. Per-filing and per-registration fees are published.
- In its own words
Sales tax, VAT and GST compliance in 90+ countries.
(numeral.com, read 29 October 2026)- Lists on its site
- Nexus monitoring; Filings & remittance; Registrations; Exemption certificate management (numeral.com)
- Pricing
- The pricing page states
Numeral charges a simple $75 per return filed plus a one-time $150 registration fee per state
(numeral.com pricing, read 29 October 2026) - Integrations it names
- Stripe; Shopify; QuickBooks; NetSuite; Chargebee; Rippling; Sage Intacct; Zoho Books (numeral.com integrations)
- Public company
- No company named “Numeral” in the SEC's list of companies with tickers, read 29 October 2026. A listing elsewhere, or a parent company, is not checked here.
Sovos
Tax compliance software for e-invoicing, indirect tax and information reporting. No price list was found on the pages read.
- In its own words
Automate e-Invoicing, indirect taxes, information reporting, identity & trust
(sovos.com, read 29 October 2026)- Lists on its site
- No module list taken from the pages we read.
- Pricing
- Not published on the pages we read, 29 October 2026. Ask for a quote.
- Integrations it names
- No integrations taken from the pages we read.
- Public company
- No company named “Sovos” in the SEC's list of companies with tickers, read 29 October 2026. A listing elsewhere, or a parent company, is not checked here.
Vertex
Indirect tax software for determination, returns and audit, with connectors for SAP and Oracle. No price list was found on the pages read.
- In its own words
The Decision-to-Defense™ global indirect tax and compliance company.
(vertexinc.com, read 29 October 2026)- Lists on its site
- Determination; Returns & reporting; Sales & use tax; VAT & GST; Vertex for SAP; Vertex for Oracle (vertexinc.com)
- Pricing
- Not published on the pages we read, 29 October 2026. Ask for a quote.
- Integrations it names
- No integrations taken from the pages we read.
- Public company
- SEC registrant: Vertex, Inc., ticker VERX (EDGAR filings, CIK 1806837).
Zamp
Managed sales tax compliance for the US and Canada, covering registrations, calculation, filing and remittance. The pricing page asks buyers to contact sales.
- In its own words
Zamp is sales tax compliance software backed by real tax experts
(zamp.com, read 29 October 2026)- Lists on its site
- U.S. Sales Tax; Canada Sales Tax; Exemption Cert Management (zamp.com)
- Pricing
- Not published on the pages we read (including zamp.com pricing), 29 October 2026. Ask for a quote.
- Integrations it names
- Adobe Commerce; BigCommerce; MS Business Central; NetSuite; QuickBooks Online; Shopify; Stripe; Xero (zamp.com integrations)
- Public company
- No company named “Zamp” in the SEC's list of companies with tickers, read 29 October 2026. A listing elsewhere, or a parent company, is not checked here.
Side-by-side tables from this guide
Sources
- European Commission, VAT in the Digital Age (ViDA). taxation-customs.ec.europa.eu/
taxation/ vat/ vat-digital-age-vida_en, read 29 October 2026. - European Commission, Minimum Corporate Taxation. taxation-customs.ec.europa.eu/
taxation/ business-taxation/ minimum-corporate-taxation_en, read 29 October 2026. - Internal Revenue Service, How long should I keep records?. irs.gov/
businesses/ small-businesses-self-employed/ how-long-should-i-keep-records, read 29 October 2026. - AICPA & CIMA, SOC 1, SOC for Service Organizations, ICFR. aicpa-cima.com/
topic/ audit-assurance/ audit-and-assurance-greater-than-soc-1, read 29 October 2026.
Spotted an error? Write to corrections@bestfinancesoftware.com; corrections are made on the page with a dated note. Vendor facts carry their own links above and on each vendor's page.