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Shopify inventory sync · multipack workflow

Sync shared stock across multiple Shopify variants — automatically.

BulkFlow is the Shopify inventory app for pack sizes, cases, and multipacks. Track one bulk count on your shelf — we keep every variant honest in real time. Stop overselling shared stock. Stop disabling variants by hand.

.myshopify.com
14-day free trial No credit card Uninstall anytime
The whole product in one formula
available_packs
= floor(bulk_units / pack_size)
Bulk on shelf
SKU: 10000E
10,000
50-pack
200
250-pack
40
500-pack
20

Sell one 500-pack → bulk drops by 500 → every variant auto-recomputes. When bulk hits 250, the 500-pack switches to “sold out” automatically.

Try it · drag the slider · switch scenarios

Watch one number ripple across three places at once.

Drag the warehouse count below. BulkFlow recomputes pack availability, Shopify Admin shows the inventory rows we'd write back, and your Storefront instantly hides or shows the matching "Add to cart" button. Same math, three surfaces — pick whichever category looks closest to your own catalog.

Scenario:
Bulk on warehouse shelf · SPARK-12OZ-BULK
2,400
cans
01,2502,5003,7505,000
BulkFlow
Warehouse pool
SKU: SPARK-12OZ-BULK
Sparkling Water — 12 oz
Bulk units · live
2,400 cans
Available packs
Single can2400
12-can fridge pack200
24-can case100
Shopify Admin
Inventory rows we write back
Product: Sparkling Water — 12 oz
3 variants · location: Main warehouse
SPARK-12OZ-1
Single can
2400
in stock
SPARK-12OZ-12
12-can fridge pack
200
in stock
SPARK-12OZ-24
24-can case
100
in stock
These rows update via Shopify's inventoryItem.set mutation whenever the bulk count changes. No manual edits.
Storefront
What customers see
YOUR-STORE.COM
Sparkling Water — 12 oz
Choose a pack size:
Single can
$2
12-can fridge pack
$18
24-can case
$32
Shopify hides variants with zero inventory automatically. Sold-out chip + greyed CTA — no merchant intervention needed.
2,400÷1=2400 Single cans available
2,400÷12=200 12-can fridge packs available
2,400÷24=100 24-can cases available
Showing 3 pack sizes for clarity. BulkFlow supports unlimited pack-size variants per pool — most real shops run 5–10 (e.g. 50 / 100 / 250 / 500 / 1,000 / case-pack / wholesale). Add as many as your Shopify catalog has.
THAT'S THE 10-SECOND VERSION

Want to see the whole loop — orders, alerts, restocking — in motion?

Run a guided 5-step walkthrough: pick your industry, simulate a purchase, watch every Shopify variant cascade, get the low-stock alert email, then close the loop with a restock.

Try the full demo
HOW IT WORKS

Automate case-pack inventory reductions — without manual reconciliation.

Every Shopify order, refund, and cancellation flows through real webhooks. One bulk pool feeds every pack-size variant. Audit log on every change.

REAL-TIME SYNC

Auto-recompute on every order

orders/paid, refunds/create, and orders/cancelled webhooks all flow through BulkFlow. We deduct the actual unit count (pack × quantity) from your bulk pool and push corrected availability back to every variant in one shot. Refunds + cancellations credit the pool. ‘Don't restock' is respected.

GDPR-COMPLIANT

Built for the Shopify App Store

Three mandatory Shopify GDPR webhooks, HMAC-verified. Audit log on every admin action. 48-hour data deletion on uninstall.

CSV-FIRST

Bulk-update 1,000 SKUs from a spreadsheet

Hash-guarded against double-imports. Reverse-on-mistake archive. Export anything you've ever changed.

LIVE OPS

One alert feed for the whole catalog

Low-stock, negative-stock, unbound variants, failed webhooks, depletion forecasts — one feed. Pivot to the right SKU in one click.

WAREHOUSE TOOLS

Barcode scanner reconciliation

Plug a USB scanner into the warehouse laptop. Walk the aisles. Every scan adjusts the bulk pool live with an audit trail per scan.

PILOT MODE

Onboard 1-2 SKUs first

Flip ON for a single item, validate against a real order, then expand. Catalog mode keeps unmanaged SKUs untouched on Shopify.

FORECASTING

Days-of-stock runway

See which SKUs run out first, based on the last 14 days of sales. Restock before Shopify shows ‘sold out'.

PRICING

Free to try. 14-day trial on Pro & BF+.

Billed by Shopify itself — appears on your existing Shopify invoice. Cancel any time from your store admin. Trials are Shopify-managed; no credit card stored with BulkFlow.

BulkFlow Free
$0
Sync up to 15 SKUs to Shopify — free forever.
Up to 15 SKUs
BulkFlow Starter
$19/mo
Single-store warehouses, getting serious.
Up to 100 SKUs
Most popular
BulkFlow Pro
$49/mo
Where most operations live.
14-day free trial
Up to 1,000 SKUs
BulkFlow BF+
$149/mo
Enterprise warehouses + multi-store ops.
14-day free trial
Unlimited SKUs
Compare featuresFreeStarterProBF+
Inventory core
Managed SKUs15 SKUs100 SKUs1,000 SKUsUnlimited
Pack-variant cascade compute
Order & refund webhooks
Audit log on every change
GDPR webhooks
Shopify sync
Push-sync to Shopify variants
Auto-suggest + push barcodes
Reverse-Create: publish products
Background sync jobs
Operations
Movement reversals
Bulk-edit packs & items
Catalog Discovery Digest emails
Inventory Health Report emails
Multi-location
Per-location inventory pools
Warehouse transfers
Support
Email support
Priority support queue
Response-time SLA
Dedicated onboarding session

All plans billed monthly through Shopify's payment rails — appears on your Shopify invoice alongside your store subscription. Cancel or change tier any time from your Shopify admin. Trials are Shopify-managed; no credit card stored with BulkFlow.

FROM THE BLOG

Playbooks for Shopify warehouses that sell in pack sizes.

See all posts

Stop disabling variants by hand.

One install. Pick which SKUs to manage. Every pack stays in sync with your shelf count automatically.

Install on Shopify