---
title: "PO Validator B2B Shopify App Profile"
description: "B2B merchants must attach a Purchase Order number to every order, but Shopify provides no native way to enforce this. Buyers skip the PO field or enter invalid data, causing fulfillment delays and ERP mismatches. PO Validator solves this with server-side validation via Shopify Functions. Buyers cannot complete checkout without a valid PO number. Configure rules: required field, min/max length, mandatory prefix, regex patterns, allowed characters, and multilingual error messages."
canonical_url: "https://shoplist.co/shopify-apps/po-validator-b2b"
markdown_url: "https://shoplist.co/shopify-apps/po-validator-b2b.md"
last_updated: "2026-10-13"
entity_type: "shopify_app"
slug: "po-validator-b2b"
source: "public Shopify app profile allowlist"
---

# PO Validator B2B Shopify App Profile

> B2B merchants must attach a Purchase Order number to every order, but Shopify provides no native way to enforce this. Buyers skip the PO field or enter invalid data, causing fulfillment delays and ERP mismatches. PO Validator solves this with server-side validation via Shopify Functions. Buyers cannot complete checkout without a valid PO number. Configure rules: required field, min/max length, mandatory prefix, regex patterns, allowed characters, and multilingual error messages.

## Quick answer
PO Validator B2B has 0 detected stores in Shoplist. This Markdown profile displays 0 public brand examples; it is not a complete customer list.

## Key facts
- Name: PO Validator B2B
- Monitoring status: First-adopter watch
- Developer: byKlemm
- Developer profile: https://shoplist.co/app-developers/startblock
- Shopify App Store URL: https://apps.shopify.com/po-validator
- Launch date: June 8, 2026
- Shoplist category: Shipping & Fulfillment
- Free plan signal: Yes
- Free trial signal: Yes

## Pricing summary
Free: Free; Starter: $4.99/month; Pro: $9.99/month

Shoplist has not yet found reliable public storefront evidence connecting a Shopify store to this app. This does not mean the app has no users. Some apps are new, admin-only, server-side, theme-independent, or otherwise difficult to detect from public storefront signals.


## App Signals
As of November 8, 2026:

- Stores running it: 0, 0.0% of the stores Shoplist tracks
- Store movement, last 28 days: +0 new stores, +0 returning, −0 removed, net 0 (estimated; 1 day held out of movement)
- Primary App Store category: Checkout - Other, #272 (14-day median position)
- Listing reviews: 0

## Public callouts
- Server-side checkout validation that buyers cannot skip or bypass
- Flexible rules: length limits, required prefix, and regex for ERP formats
- Character rules: whitelist allowed characters and block unwanted spaces
- Regex rules: validate PO formats against ERP and SAP number patterns
- Supports EN, DE, FR, and ES error messages out of the box
## Shopify App Store categories
- Checkout - Other

## Data note
Profile updated: October 13, 2026. This is the profile revision date, not a guarantee that every store was checked on that date.
Public snapshot built: 2026-11-08 12:04:09.003454\+00
Detection metrics refreshed: 2026-11-08 10:00:00.19319\+00
Public app evidence date: 2026-10-13 20:15:15.781707\+00
This generated Markdown profile intentionally exposes only public, stable app-profile fields and a small public app-stack sample from Shoplist. It excludes private contact data, people data, internal scores, crawl provenance, full datasets, and unstable operational fields.

## Related links
- [HTML app profile](https://shoplist.co/shopify-apps/po-validator-b2b)
- [Shopify apps directory](https://shoplist.co/shopify-apps)
- [Shoplist data methodology](https://shoplist.co/data-methodology.md)