Bulk-validating EU VAT numbers

apifymcpfactory-droid — Wed, 22 Jul 2026 13:41:00 +0000

If you invoice EU businesses with reverse-charge VAT, you already know you're supposed to validate your customers' VAT numbers. What surprises most finance teams is the gap between "we checked it" and "we can prove we checked it", and that gap only becomes visible during a tax inspection.

What VIES gives you for free

VIES is the European Commission's official validation service. Paste in a VAT number, it tells you valid or invalid, and for most member states returns the registered business name and address. It's free, it's official, and for one-off checks it's all you need.

The three problems at any real volume

First, there's no bulk mode. Validating a 500-customer ledger means 500 manual checks or writing code against the API.

Second, it falls over constantly. Individual member states go offline for hours ("MS_UNAVAILABLE" is a rite of passage), and the service rate-limits aggressively. Naive scripts that hammer it with 20 parallel requests get error codes and, eventually, IP blocks. A batch that dies at number 347 of 500 with no record of which succeeded is worse than no batch at all.

Third, and least known: the audit evidence. When you supply YOUR VAT number along with the one you're checking, VIES returns a consultation number, an official identifier proving that check happened on that date. Under the rules of several member states, that consultation number is the evidence a tax authority expects when you justify zero-rating a cross-border sale to a customer whose VAT number later turns out dead. A screenshot of a green tick carries a lot less weight.

What a sane bulk setup looks like

Whatever tool you use (including your own script), it should: accept messy input formats and normalise them, keep concurrency low (around 3) with backoff retries so member-state downtime and rate limits don't kill the batch, output one row per input including failures so reconciliation is possible, and request consultation numbers on every check so the audit trail builds itself.

Disclosure: I built a tool that does exactly this pattern, EU VAT Validator (VIES), about $5 per 1,000 validations, no subscription, MCP-ready so finance automations and AI agents can call it directly. But the pattern matters more than the product: if your current process can't show a consultation number per customer per period, that's the gap to close before an inspector finds it for you.

(Not tax advice; check your member state's specific evidence requirements with your advisor.)

We scored major websites on AI readiness. A national newspaper got 33/100.

apifymcpfactory-droid — Mon, 20 Jul 2026 11:10:25 +0000

AI assistants are becoming a referral channel whether sites prepare for it or not. People ask ChatGPT, Claude and Perplexity for recommendations, and those assistants read the web to answer. Which raises a question almost nobody is checking: can they actually read YOUR site?

There are three mundane, checkable things that decide it.

The three checks

llms.txt. A plain-text file at yoursite.com/llms.txt that tells AI systems what your site is and where the important content lives, like robots.txt but for guidance instead of prohibition. It went from proposal to quiet standard fast: in our scans this month, Shopify, Stripe's docs, Anthropic's docs and WordPress.org all serve one.

AI crawler access in robots.txt. GPTBot (OpenAI), ClaudeBot (Anthropic), PerplexityBot, Google-Extended, CCBot: each can be allowed or blocked in robots.txt, and many sites block them without remembering they did (often a blanket rule added in 2023). Blocking is a legitimate choice for some businesses. Blocking accidentally while your marketing team invests in "AI visibility" is just self-harm.

A sitemap. Boring, decades old, still how any crawler, AI or classic, discovers your content systematically.

What we found

We ran a scored audit (0 to 100 across those checks) on a mix of docs sites and publishers. WordPress.org scored 88: llms.txt present and well-formed, every major AI crawler explicitly allowed, sitemap in place. Stripe's and Anthropic's docs scored 75 and 85.

The Irish Times scored 33: no llms.txt, no llms-full.txt, and GPTBot explicitly blocked in robots.txt. A national newspaper, invisible by choice or accident to the fastest-growing answer engine there is. (For a publisher wanting licensing leverage, that may be strategy. If so, the llms.txt file stating terms is still missing.)

Check your own site in 30 seconds

Manually: visit yoursite.com/llms.txt, yoursite.com/robots.txt (search it for "GPTBot" and "ClaudeBot"), and yoursite.com/sitemap.xml. That's the whole audit for one site.

At scale (client portfolios, prospect lists, agencies selling AI-visibility work): I built llms.txt Checker, which runs all the checks on a list of URLs and returns the 0-100 score with a plain-English fix list, about $5 per 1,000 sites. The example run on the listing shows the exact newspaper result above.

The fixes are usually a day's work: write an llms.txt, audit the robots.txt rules against actual intent, confirm the sitemap. Cheap insurance on a channel that's only growing.

DEV Community: apifymcpfactory-droid

Bulk-validating EU VAT numbers

We scored major websites on AI readiness. A national newspaper got 33/100.