It's one of those topics everyone dreads and that's most expensive to ignore. Many online businesses start out applying the standard Spanish VAT rate to everyone, without stopping to think that the rules change as soon as you start selling outside Spain, or even depending on the specific type of product. It's not a minor issue: a VAT application error discovered in a tax inspection can mean surcharges, late payment interest and penalties that eat up months of margin in one go. This guide doesn't replace a tax advisor (and it shouldn't), but it does help you understand what questions to ask before it's too late.
VAT within Spain: the simpler part
For sales to customers within Spain, the VAT rate corresponding to the product applies: the general 21% for most items, the reduced 10% for certain products (like some foods or specific services), and the super-reduced 4% for a limited list of essential goods. Each product page in your store needs the correct rate associated with it, and a mistake here (applying 21% to something that should carry 10%, or vice versa) creates a discrepancy that sooner or later surfaces in the accounts.
When you start selling to other European Union countries
This is where most businesses get lost. Since 2021, the VAT system for online sales within the EU changed with the introduction of the scheme known as OSS (One Stop Shop). Before that change, different sales thresholds existed per country, which, once exceeded, required registering for VAT in that specific country. Now, with OSS, there's a single combined threshold of 10,000 euros a year in sales to consumers across the whole EU (adding up all countries together, not separately): below that threshold, you can keep applying Spanish VAT; above it, you must apply the VAT of the customer's destination country (which varies: for example, the general rate in Germany differs from that in France or Italy), and you can declare all that VAT centrally through the OSS system in Spain, without having to register individually in each country.
What happens if you sell outside the European Union
Sales to countries outside the EU (the UK post-Brexit, the United States, Latin America) are considered exports and are generally exempt from Spanish VAT, but the customer may have to pay tariffs and import VAT in their own country when receiving the package. It's essential to be transparent with the customer about this possibility on the product page or at checkout, because a customer who gets an unexpected customs bill after already having paid the full price feels cheated, even though you technically didn't cheat them.
The special case of digital products
If you sell info-products, online courses, software or any digital product, the VAT rules differ from those for a physical product: for sales to individual consumers within the EU, the applicable VAT is always that of the buyer's country, from the very first euro sold, without the 10,000-euro threshold that applies to physical products. This means that, technically, if you sell an online course to a customer in Portugal, you should apply Portuguese VAT from the first sale, something many small info-product creators aren't aware of and that can lead to unpleasant surprises in an audit.
Tools that help you avoid mistakes
The good news is you don't need to calculate this by hand. Both Shopify and WooCommerce have tax configuration modules that, when properly set up with the customer's location and product type, automatically apply the correct VAT based on the destination country. What matters is configuring it correctly from the start (with help from your tax advisor) and reviewing it periodically, because each country's VAT rates can change, and a setup that was correct two years ago may now be outdated.
A real case: the surprise of an unnoticed exceeded threshold
A Spanish fashion accessories store started selling organically to customers in France, Italy and Germany thanks to SEO and some occasional advertising, without ever changing its VAT configuration, which kept applying the Spanish 21% to everyone. When their accountant reviewed the year's figures, they discovered the store had exceeded the 10,000-euro EU sales threshold several months earlier, meaning they'd been applying incorrect VAT to a large chunk of those sales for some time. They had to retroactively regularise the situation and register for the OSS system, a process they could have avoided by regularly checking that threshold from the moment they started selling outside Spain.
Electronic invoicing and VeriFactu: what's coming
Besides VAT, it's worth keeping the VeriFactu regulation on your radar, which progressively requires self-employed people and companies' invoicing systems to meet specific technical requirements for traceability and invoice immutability, aimed at making tax fraud harder. If your online store generates invoices automatically, it's your responsibility to make sure the software you use (whether the ecommerce platform's own system or a connected invoicing system) complies with these requirements within the deadlines set by the regulation.
Common mistakes when configuring taxes on the store platform
Beyond understanding the regulation, there are practical configuration mistakes that repeat frequently in small stores: leaving the country of origin misconfigured on the platform, not updating VAT rates after a regulatory change in a specific country, or applying the same VAT rate to products that actually carry different rates within the same order (for example, a bundle combining a standard-rate product with a reduced-rate one). Reviewing the tax configuration at least once a year, ideally with your accountant, helps catch these errors before they pile up across dozens or hundreds of incorrectly invoiced orders.
What documentation is worth keeping in case of an audit
In the event of a tax authority review, having well-organised documentation justifying how VAT was calculated on each sale (customer's destination country, rate applied, justification of the EU sales threshold at a given point) saves a huge amount of time and reduces the risk of penalties for formal errors, even when the substance is correct. Most ecommerce platforms and connected invoicing systems automatically generate these records, but it's worth periodically verifying they're being saved completely and accessibly, rather than just trusting that "the system already handles it."
When it's worth having a dedicated fiscal representative abroad
For businesses selling significant volumes in a specific foreign market, beyond the OSS system there are situations where appointing a local fiscal representative or registering directly in that country becomes necessary, particularly when using local fulfilment warehouses (as with some Amazon logistics programmes) or reaching certain thresholds in specific regulated sectors. This is a more advanced step than most small businesses need, but it's worth having on the radar as the business grows internationally, so it doesn't come as a surprise when a specific market starts requiring it.
VAT mistakes that keep repeating at small online businesses
Beyond the big regulatory changes, there's a set of small, very common oversights that cause problems disproportionate to their size. The first is not checking the VAT applied to shipping costs: generally, shipping follows the same VAT rate as the order's main product, but when a single cart mixes products with different rates (say, a standard-rate product and a reduced-rate one), correctly calculating which portion of the shipping corresponds to each rate is a detail many store setups don't handle well out of the box and that needs manual review.
The second common oversight is not updating the tax configuration after a change in accountant or administrative lead. When whoever handles the accounting changes, it's easy for certain fine-tuned settings (EU sales thresholds, reduced rates applied to specific products) to get lost in the handover if they aren't documented in writing, leaving the new person in charge inheriting a setup nobody fully understands or thoroughly audits. The third mistake, especially common at businesses selling across several marketplaces besides their own store, is not verifying VAT is calculated consistently across all channels: it's common for the own store's setup to be correct while the marketplace applies a different calculation nobody has checked, creating an accounting discrepancy that, in the worst case, only surfaces during an audit.
The fourth, deeper mistake is treating tax matters as something settled once at business launch and never revisited. VAT regulation for online sales, especially around cross-border trade within the European Union, has changed several times in recent years and is reasonably expected to keep changing. Scheduling an annual review with your accountant, specifically focused on whether the store's tax setup is still correct under current regulation, costs little time and stops a regulatory change from going unnoticed for months.
A fifth oversight, especially relevant for fast-growing businesses, is not telling the accountant as soon as sales start in a new country, waiting instead for the quarterly or annual filing to mention it in passing. The sooner a change like this is communicated, the more room there is to adjust the tax setup before months of sales pile up under incorrect treatment, which is exactly what turns a simple fix into a costly, retroactive regularisation.
Frequently asked questions
Do I need a tax advisor even if my store is small?
It's highly recommended once you start selling outside Spain or growing in volume, because VAT mistakes are usually discovered late and are expensive to correct. The cost of an advisor is, in the vast majority of cases, much lower than that of a penalty for incorrect tax application.
What exactly is the OSS system and how do I register?
OSS (One Stop Shop) is the system that lets you centrally declare, from Spain, the VAT on your sales to consumers across the whole European Union, without having to register individually in each country. Registration is done through the Tax Agency's electronic office, usually with help from your tax advisor.
Is the 10,000-euro threshold per country or total?
It's a combined threshold: all your sales to consumers across the entire European Union (outside Spain) are added together, not calculated separately country by country. Once the total sum exceeds 10,000 euros a year, the destination country's VAT regime kicks in.
Do I have to charge VAT if I sell to a business (B2B) in another EU country?
B2B sales within the EU, when the buyer has a valid intra-community VAT number, are usually exempt from Spanish VAT under the reverse charge mechanism, though there are specific verification and reporting requirements worth reviewing with your advisor.
What happens with VAT if I sell on Amazon as well as my own store?
It depends on the model: if you handle your own logistics, you manage VAT the same way as in your store, but if you use Amazon's fulfilment services with warehouses in different countries, additional tax obligations can arise in those countries, a scenario that requires specific advice before activating it.
How do I know what VAT rate to apply to a specific product in Spain?
There are official Tax Agency listings detailing which products and services carry the reduced or super-reduced rate; for any doubt about a specific product, the safest approach is to check directly with your tax advisor before configuring the rate in the store.