Sales tax and VAT compliance software

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Sales tax and VAT compliance software covers two different jobs: calculating and filing US sales tax where you have nexus, and registering for, charging and filing VAT in the UK and EU. Few tools do both equally well. US sellers usually pick one of three setups, and the deciding question is who files each return, not who calculates the rate.

• One global tax engine (Avalara, Sovos, Vertex): the widest coverage, with enterprise pricing and setup.
• Two specialists (a US sales tax tool plus a UK/EU VAT provider): the most common setup, with two logins and two deadline calendars.
• One partner for both (for example AVASK with the Infiniti3 platform): one team registers and files on both sides; check which parts run in software and which are a managed service.

You hit economic nexus in a handful of states, your sales tax finally runs on autopilot, and now Amazon.co.uk or Amazon.de is next. This is where many US sellers find out that the tool they use for sales tax doesn’t do VAT, or does the math but not the registrations, returns and tax-office letters that VAT actually involves.

This guide is for US ecommerce and Amazon sellers of physical goods who already collect sales tax and are adding the UK or EU. It covers what changes when you cross the Atlantic, what a sales tax tool does and doesn’t do for VAT, the three ways to run both, and how the main sales tax and VAT compliance software options compare. If you are still working out where you owe US tax, start with when US economic nexus kicks in.

Disclosure: AVASK provides one of the options compared here (the Infiniti3 platform plus managed compliance). We checked every competitor fact on the vendor’s own website on 28 September 2026, and we link to government sources for the rules.

Sales tax vs VAT: why one tool rarely covers both well

US sales tax and VAT are both consumption taxes, but they ask very different things of your software. Sales tax is charged once, at the final sale, by states and local governments. VAT is charged at every stage by national governments, and it comes with registrations, local-format returns, invoice rules and evidence that a sales tax engine was never built to produce.

Most US tax tools grew up solving rate calculation across the 45 states and DC that levy a statewide sales tax, plus thousands of local jurisdictions. VAT flips the problem: the rate is easy to find, but registering, filing and keeping evidence in each country is where the work is. For the full side-by-side, see how VAT differs from US sales tax.

What changes when you start selling in the UK and EU

Your US thresholds stop mattering the moment you sell into the UK or EU. As a business established outside both, you have no sales threshold to stay under: holding stock in a UK or EU warehouse, including Amazon FBA, triggers a VAT registration from the first sale, and shipping parcels straight to consumers brings its own rules.

The triggers a US seller meets most often in the UK and EU.

Selling into the UK

The UK has a VAT registration threshold of £90,000, but it only applies to UK-established businesses. HMRC is explicit that the threshold does not apply to non-established businesses: if you make taxable supplies in the UK, for example by selling from UK FBA stock, you register from the first sale.

Online marketplaces change who pays the VAT, not whether you register. Under the UK online marketplace VAT rules, Amazon, eBay and other marketplaces account for VAT on imports of £135 or less and on goods located in the UK that overseas businesses sell. You still need a UK VAT number for the stock you import, to pay and reclaim import VAT, and to report your sales. Anything you sell outside the marketplace, such as orders through your own Shopify store or to business customers, is VAT you charge and pay yourself.

Every UK VAT return is filed through software under Making Tax Digital for VAT, so whichever tool you choose needs an MTD-compatible connection to HMRC. For the step-by-step, see how to register for UK VAT as an overseas seller.

Selling into the EU

The EU’s €10,000 threshold for cross-border sales to consumers is only available to sellers established in a member state, according to the European Commission. For a US company, three situations cover most of what you will meet:

• Stock in an EU warehouse. If Amazon or a 3PL stores your goods in a country, you need a VAT registration there. With Amazon’s Pan-European FBA program that can mean several registrations at once, and stock moving between countries has to be reported.
• Cross-border sales from EU stock to EU consumers. The Union One Stop Shop (OSS) lets you declare these in one quarterly return instead of registering in every destination country. It does not replace the registration where your stock is held. Marketplace sales by non-EU sellers are usually the marketplace’s to declare, so OSS matters most for your own-site orders.
• Parcels shipped from the US to EU consumers. For consignments of €150 or less, the Import One Stop Shop (IOSS) lets you charge VAT at checkout; a US company needs an EU-based intermediary to use it. Since 1 July 2026 the EU also charges a temporary €3 customs duty on low-value parcels, per item category, until July 2028.

Some countries also require a fiscal (tax) representative. The UK doesn’t. France, for example, requires one for US companies, and several other EU countries have similar rules. See OSS and IOSS registration for how the schemes work in practice, and the end of duty-free for low-value parcels for the 2026 customs changes.

Beyond VAT: EPR, customs and reporting

• EPR. Packaging, electronics and batteries need extended producer responsibility registrations in countries such as Germany and France, and marketplaces ask for the numbers. Since 12 August 2026, sellers established outside the EU must also appoint an authorized representative. See EPR registration for Amazon sellers in Europe.
• Customs. Importing stock needs an EORI number, customs declarations and import VAT. See UK and EU customs clearance and EORI.
• Reporting. Under DAC7 seller reporting, marketplaces share your sales data with EU tax authorities, so gaps between what Amazon reports and what you file are visible.
• What’s next. The EU’s VAT in the Digital Age (ViDA) reforms add a single VAT registration and a module for moving your own goods between countries from 1 July 2028. That should cut some registrations; it won’t remove the need to file.

What your US sales tax tool does, and what it doesn’t do for VAT

A good US sales tax tool calculates rates, tracks nexus and files state returns. It usually won’t register you for VAT, file returns in each EU country’s format, act as your fiscal representative or answer a letter from the German tax office. That gap, not calculation, is what you are really buying for.

Since the US Supreme Court’s 2018 South Dakota v. Wayfair decision, US tools have been built around economic nexus: watching sales by state, registering you when you cross a threshold and filing returns. They also handle marketplace facilitator laws in every sales-tax state, which make Amazon, Walmart and others collect on your behalf.

Some US tools have stepped back from international tax altogether. TaxJar, for example, no longer offers international calculations to new customers and points them to Stripe Tax. Others calculate VAT but hand registrations and filings to partners.

There is one more thing a US tool rarely sees: the whole picture across channels. If you sell on Amazon and through your own store, marketplace-collected tax and tax you collected yourself have to be reconciled before each return, on both sides of the Atlantic. Our guide to what Shopify collects and what you still owe shows how that works in the US.

Three ways to run sales tax and VAT together

There are three workable setups: one global indirect tax engine that covers both, two specialist providers (one for US sales tax, one for UK and EU VAT), or one compliance partner that registers and files on both sides. The right one depends on your size, your channels and how much of the filing you want to own.

Who files each return is the real difference between the three setups.

Option 1: one global indirect tax engine

Indirect tax compliance software from Avalara, Sovos or Vertex covers US sales tax and VAT under one contract, often with managed filing and fiscal representation as add-ons. It suits companies with an ERP, a tax team and volume in many countries. Expect quote-based VAT pricing and a longer implementation. Global tax compliance software at this level is powerful, but smaller marketplace sellers often pay for coverage they don’t use.

Option 2: two specialists

Keep your US sales tax tool and add a UK and EU VAT provider that registers and files for you. This is the most common setup for Amazon and Shopify sellers because each provider is strong on its own side. The cost is coordination: two logins, two deadline calendars, two sets of data pulled from the same Amazon account, and nobody who owns the whole picture.

Option 3: one compliance partner for both

A single partner runs both regimes, usually as software plus specialists who file for you. You get one deadline view, one data connection to your marketplaces and one team for cross-border tax compliance questions. Check exactly which parts are automated in the platform and which are a managed service, and whether the partner files directly with tax authorities. AVASK works this way through the Infiniti3 compliance platform; Lovat (Lappa) offers a self-service software version.

Sales tax and VAT compliance software compared (2026)

The best sales tax and VAT compliance software for a US seller of physical goods is the one that files both sides in the countries you actually sell in. Avalara and Sovos cover both at enterprise scale; Kintsugi, Lovat and Stripe Tax offer software routes with different limits; AVASK combines the Infiniti3 platform with specialists who file for you.

Checked on each vendor’s website on 28 September 2026. Prices and features change often; confirm with the vendor before you sign.

How to read the table. A tick for “VAT” on a pricing page can mean anything from rate calculation to full registration and filing. The “Who files” column is the one that decides your workload. A few notes on fit for a US seller of physical goods:

• Avalara: one vendor across US and UK/EU, including IOSS intermediary and fiscal representation. Watch per-state US pricing (with a three-state minimum on its Core Compliance plan) and quote-only VAT.
• Sovos and Vertex: strong for ERP-led enterprises that want managed VAT; neither lists an Amazon integration.
• Stripe Tax: a good fit for direct-to-consumer stores that check out through Stripe. Amazon sales aren’t Stripe transactions, so they sit outside it, and non-US filing runs through partners at extra cost.
• Kintsugi: transparent US pricing with a path to the UK and EU, but VAT sits on a custom plan.
• Anrok: built for SaaS; physical goods support is newer and Amazon connections are on request.
• Quaderno: low-cost calculation and reports for smaller sellers, with filing as an add-on.
• Lovat (Lappa): broad coverage at low entry prices; by default you check and submit returns yourself.
• Taxually: strong on EU and UK VAT plus EPR, but its US sales tax product isn’t available for ecommerce businesses today.
• AVASK: one team for UK and EU VAT, EPR, customs and US sales tax, with direct filing through Infiniti3 where tax authorities offer APIs. The US side is a managed service until it moves into the platform.

If you only need the VAT side, see our 2026 comparison of VAT compliance software, which reviews ten VAT tools in depth. If you’re moving from a provider that has left the market, such as VAT Services on Amazon (ended 31 October 2024) or Taxdoo (VAT services ended 30 April 2026), here is how switching VAT provider works.

How to choose: 10 questions to ask any provider

Ask who files, where, and what’s included. Rate calculation is table stakes; registrations, direct filing, representation and evidence are where providers differ, and where penalties come from.

1. Who files each side? Get it in writing for US states, the UK and every EU country you’ll sell in.
2. Which countries are filed directly, and which through a partner? Direct API filing is faster and leaves a cleaner audit trail.
3. Are registrations included, and how long do they take? A late VAT number delays your launch or creates back-dated tax.
4. Do they provide a fiscal representative or IOSS intermediary where one is required?
5. Can they ingest Amazon’s VAT Transaction Report and your Shopify data without manual exports?
6. Do they reconcile marketplace-collected tax against tax you collected yourself, in the US and in Europe?
7. Is there one view of deadlines for US states and VAT countries?
8. What evidence do they keep? Look for filing receipts, proof of payment and invoices stored against each period.
9. Who answers tax-office letters, and in which languages?
10. What’s the pricing model, and what costs extra? Ask per state, per country and per filing, and whether EPR and customs are included.

Which setup fits your stage?

Match the setup to your footprint. A US-only seller needs a sales tax tool; the first UK or EU stock placement adds VAT registrations; Pan-European FBA or several countries is where one accountable partner pays off.

“We’ve hit sales tax nexus in several states and we’re expanding into Europe. What handles both?”

Separate calculation from compliance. At checkout, Amazon collects the tax on most marketplace sales on both sides of the Atlantic, and your store platform or a tool like Stripe Tax calculates it on your own site. What no checkout tool does is register you, file returns in each state and country, keep the evidence and deal with tax offices. So the real choice is between keeping your US tool and adding a UK and EU provider that files, or moving both sides to one partner with one deadline view. Either works. What fails is assuming the checkout tool covers the filing.

What running both actually costs

Budget by filings, not by software seats. Your cost is roughly the number of US state returns plus the number of VAT returns you file each year, plus registrations, representation and EPR, and the time it takes to reconcile them.

Costs that rarely appear on pricing pages:

• Fiscal representative and IOSS intermediary fees in countries that require them.
• Zero-tax state returns: in many states your marketplace sales count toward your nexus threshold, so you may have to register and file even when Amazon collected everything.
• EPR scheme fees and registrations per country and product category.
• Registration lead times: AVASK currently quotes about 6–10 weeks for UK VAT and 2–3 months for Germany. A late registration delays your launch or creates back-dated liabilities.
• The hours spent reconciling two providers’ data every period.

How Infiniti3 handles sales tax and VAT

Infiniti3 is AVASK’s compliance platform. It connects your sales channels, calculates and validates VAT, files directly with tax authorities where APIs exist and keeps the evidence, while AVASK specialists register and file for you. US sales tax is handled today by AVASK’s specialists and moves into the platform by the end of Q4 2026.

• Connect: Amazon, Shopify (through the Infiniti3 app), eBay and 20+ other channels, with marketplace reports pulled in automatically.
• Calculate and validate: VAT and EPR calculation engines with a validation service that catches errors before they reach a return.
• Submit: direct filing through tax-authority APIs in the UK (HMRC), Germany, Spain, the Czech Republic, Poland and for IOSS. AVASK’s team files everywhere else.
• Prove: filing receipts, proof of payment and captured invoices kept against every period.
• People: 420+ specialists in 12 countries and 25 languages handle registrations, fiscal representation where required, EPR and tax-office correspondence.
• US sales tax: nexus review, state registrations and filings by AVASK specialists today. See US sales tax registration and filing.

Infiniti3 VAT compliance view: liability, deadlines, filing receipts and proof of payment per country (demo data).

Explore UK and EU VAT registration and filing with AVASK, or see how the platform works.

FAQ

Run sales tax and VAT without two sets of blind spots

Selling across the Atlantic means two tax systems with different triggers, returns and evidence. Whichever setup you choose, make sure every return has an owner, every deadline sits in one view, and your marketplace data flows in without spreadsheets.