The Scenario
Your B2B SaaS billing team is about to migrate to a new pricing model that displays tax-inclusive prices for EU customers. Before any invoices go out, every European customer's VAT number needs to pass validation — zero-rated invoices issued to invalid VAT numbers expose you to liability. You have 150 rows in an Excel workbook: column A is the ISO country code, column B is the VAT number. The migration is scheduled for next Tuesday and this validation pass blocks everything downstream.
The bad version:
- Open Quaderno's tax ID validation tool, paste the first country code and VAT number, check the result, switch back to the workbook, type Valid or Invalid into column C
- Repeat 149 more times across an afternoon
- Notice at row 80 that some VAT numbers have spaces in them and Quaderno returns Invalid for those even though the underlying number is correct — now you have to go back and strip spaces from all the rows you've already checked
The migration timeline does not have slack for a manual validation rework.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent inside your Excel workbook that reads your VAT numbers and calls Quaderno's tax ID validation endpoint for each one.
Validate all 150 VAT numbers in column B (country codes in column A) using Quaderno and flag each row as Valid, Invalid, or Unknown in column C of this Excel sheet
What You Get
- Every VAT number is checked against Quaderno's validation service using the correct country context
- Results land in column C as Valid, Invalid, or Unknown — Unknown indicates the validation service couldn't reach the issuing jurisdiction
- Rows with formatting issues (spaces, dashes, lowercase prefix) are normalized before the call so you don't get false Invalids
- The entire 150-row column resolves in one operation
What If the Data Is Not Quite Ready
The VAT numbers have inconsistent formatting — spaces, dashes, mixed case
Before validating, clean the tax IDs in column B: strip spaces and dashes, uppercase the country prefix, update column B — then validate each cleaned ID against the country code in column A and write Valid, Invalid, or Unknown into column C
I need to know not just valid/invalid but also the registered company name for each valid number
For each row, validate the tax ID in column B against country code in column A using Quaderno — write Valid or Invalid to column C; for Valid rows, write the registered company name returned by Quaderno to column D
Some rows are missing the country code — the full VAT number including the country prefix is in column B
For rows where column A is blank, extract the two-letter country prefix from the VAT number in column B, fill it into column A, then validate the remaining digits against the country and write Valid, Invalid, or Unknown to column C
Strip formatting, validate all numbers, flag invalid ones, and generate the ready-to-invoice list in one shot
For each row: clean the tax ID in column B (strip spaces and dashes, uppercase prefix), update column B; validate the cleaned ID against country in column A using Quaderno; write Valid, Invalid, or Unknown to column C; for Invalid rows write Do Not Invoice to column D; for Valid rows write Ready to column D
Try It
Get the 7-day free trial of SheetXAI and open the Excel workbook where your customer VAT numbers are staged, then ask it to run the validation pass before the migration goes live. Also see: bulk looking up tax rates from an Excel workbook, and the hub overview of all Quaderno connection methods.