Fiscal ID: B2B VAT & Tax ID vs King Checkout Validation
Two Shopify apps, side by side: detected stores, momentum, reviews, plans, listed features and who runs each. Store counts as of Nov 2, 2026 for Fiscal ID, Nov 5, 2026 for King Checkout Validation.
The short answer
- Only King Checkout Validation lists a free plan. Paid plans start at $6.99/month for Fiscal ID and $4.99/month for King Checkout Validation.
- King Checkout Validation lists 13 features Fiscal ID’s listing doesn’t mention, including Cart-based, Checkout alerts, Collection-specific.
Head to head
- Australia
Momentum
New reviews each month
Review pace is the clearest public read on how fast an app is winning new merchants.
Launch plan
- · All countries and ID types included
- · Cart, drawer, thank-you, account blocks
- · Unlimited orders, email support
Free
- · Create and test validation rules
- · Free for development stores
Basic
- · Block PO box addresses
- · Live chat and email support
- · Require VAT numbers
- · Require house, apartment or suite number
Premium
- · All Basic features
- · Build regular expression rules
- · Combine cart and customer conditions
- · Detect non-Latin characters
- · Match keywords in checkout fields
- · Set checkout field length limits
Coverage counts what each App Store listing names. Every feature, checked off app by app, is in Shoplist.
See every featureBusiness buyers need a valid tax ID on the invoice, but checkout has no field for it unless you are on Plus. Fiscal ID adds one to the cart, thank-you page and customer account, and on Plus to the checkout page too. It validates as the buyer types: EU VAT, check digits for Spain, Argentina, Chile, Peru and Colombia, and 80+ countries, with your own label per country.
Use checkout validation to check shipping and billing address fields before orders are placed. Block PO boxes, require house or apartment numbers, and check postcode/ZIP, email and VAT/tax ID formats. Match phone country codes to address countries. Set order limits by cart amount, quantity or weight, with conditions for products, customer tags and countries. Use keyword, regex and field-length checks.
- Works on Basic, Shopify and Advanced plans. No Shopify Plus needed.
- Check-digit validation for ES, AR, CL, PE, CO, EU VAT and 80+ more countries.
- Require the ID always, only for invoices, or above an order amount.
- Saved to order and customer metafields any invoicing app can read.
- Verifies presence of house/apartment number in addresses
- Validates completion of customer's VAT number (Tax exemption)
- Filters out Post Office (PO) Box addresses
- Field Length Validation, Custom Keyword and Regular Expression Validation
All the numbers
Every figure, side by side
A green dot marks the app ahead on a measured figure. Estimates, gaps and apps that leave no storefront trace never take the lead.
Adoption
| Measure |  Fiscal ID |  King Checkout Validation |
|---|---|---|
| Detected stores | Not published | 1 |
| Net store change, 28 days | 0 | 0 |
| Stores added, 28 days | Not enough data | Not enough data |
| Big-brand share | Not enough data | Not enough data |
| Top store categories | Not published | Home & Garden |
| Top store countries | Not published | Australia |
Reviews
| Measure | Fiscal ID | King Checkout Validation |
|---|---|---|
| App Store rating | Not published | 5.0 ★ |
| App Store reviews | Not published | 20 |
| New reviews, 28 days | Not enough data | 0 |
| Reviewers a year or more in | Not enough data | Not enough data |
Pricing
| Measure | Fiscal ID | King Checkout Validation |
|---|---|---|
| Free plan | Not listed | Yes |
| Lowest paid monthly plan | $6.99/month | $4.99/month(ahead) |
| Longest free trial | 14 days | 7 days |
| Plans listed | 1 | 3 |
Listing
| Measure | Fiscal ID | King Checkout Validation |
|---|---|---|
| Shopify category rank | #237 | #24 |
| Shopify App Charts | Not on this week’s charts | #24 in Checkout - Other |
| Built for Shopify | No | Yes |
| Launched | Sep 18, 2026 | Mar 15, 2024 |
| Languages | 2 | 1 |
| Developer | Fiscal ID Labs | Lightcone |
FAQ
Fiscal ID and King Checkout Validation: common questions
- Is Fiscal ID or King Checkout Validation cheaper?
- Only King Checkout Validation lists a free plan. Paid plans start at $6.99/month for Fiscal ID and $4.99/month for King Checkout Validation. Shoplist compares base prices only between monthly plans in the same currency; usage charges and annual plans vary, so check each plan’s limits.
- What features does each app list that the other doesn’t?
- Fiscal ID lists 4 the others don’t mention, such as Cart drawer, Custom notes, Custom rules, Multi-language. King Checkout Validation lists 13 the others don’t mention, such as Cart-based, Checkout alerts, Collection-specific, Custom messages. A feature missing from a listing may still be supported; this compares what each App Store listing says.
- Where does this comparison’s data come from?
- Shoplist crawls Shopify storefronts to detect which apps each store runs, and reads each app’s Shopify App Store listing for reviews, pricing, features and integrations. Store counts are as of Nov 2, 2026 for Fiscal ID, Nov 5, 2026 for King Checkout Validation; estimated figures are labeled.
How Shoplist compares apps
Store counts come from Shoplist’s crawl of Shopify storefronts, which detects the apps each store runs; they are as of Nov 2, 2026 for Fiscal ID, Nov 5, 2026 for King Checkout Validation. Reviews, ratings, plans, features and integrations come from each app’s Shopify App Store listing. 28-day figures are labeled when estimated, and a figure that is missing or estimated never decides who leads. Read the methodology.