Case Study HVAC Trade Supply 🇦🇺 Australia
Climat Trade Centre

From paper dockets to
same-day invoicing.

Digiwah built Climat Trade Centre a custom Zoho Creator delivery app: proof-of-delivery captured on the phone, status pushed straight into Unleashed, and the invoice issued automatically through Xero. Live, in daily production.

Same‑day
Delivery → invoice
~30s
Job auto-create
Zero
Manual entry
Live
In production
The Client

Climat Trade Centre

A Victorian HVAC trade supplier of Daikin ducted reverse-cycle systems, Brivis gas heaters, wall splits, controllers, and solar & battery, sold at trade prices to installers across the state.

“We hold the stock. Always ready when you need it.”

But holding the stock means moving it. A delivery fleet runs orders out to trade customers every day, and that fleet ran entirely on paper.

Industry
HVAC trade supply
Base
Epping, Victoria
Operation
Trade counter + delivery fleet
Already ran
Unleashed + Xero
DaikinBrivisWall splitsSolar & battery
The Challenge

The delivery that couldn't invoice itself

Every delivery created a paper docket. The invoice couldn't go out until that docket was physically chased back to the office and keyed in by hand. Cash flow waited on paper.

Delivered
Paper docket
Chased to office
Re-keyed by hand
⏳ days lost
Invoice (late)
Slow cash flow
Invoices sat idle until a paper docket made it back to the office.
Invoice disputes
Partial deliveries were billed in full, then argued over.
No live visibility
The office couldn't see who was where, or what was done.
Double data entry
Delivery details were keyed in twice, by hand, after the fact.
The #1 pain was simple: invoicing was delayed because of paperwork. Alroy Augustus, owner, Climat Trade Centre
The Solution

One app, wired into the tools
they already trusted.

A custom delivery app on Zoho Creator sits between the systems Climat already ran. Unleashed creates the jobs. Climat dispatches and captures proof of delivery. Unleashed fires the invoice through Xero. Nothing was ripped out. We closed the gap in the middle.

Their inventory
Unleashed
Sales orders & stock
C
We built this
Climat
Dispatch + driver app
Downstream
Xero
Invoice issued
Watch it run

From flagged order to issued invoice

Press play in your head, or just watch. This is the exact path every delivery now takes, in production.

Climat Delivery System
Unleashed · Sales Order
SO-4471Open
Geelong HVAC Installs
Daikin FDYAN160 ducted×1
Brivis Buffalo 20 heater×2
Zone controller kit×1
Belmont VIC 3216 · flag for delivery
DELIVERY
Unleashed
Climat
SO-4471 · new delivery job
Geelong HVAC Installs
4 line items · auto-imported
✓ Created in ~30s · 0 manual steps
Unassigned
SO-4471
Geelong HVAC
JMJake M.
drop zone
RSRavi S.
Assigned to Jake M. · status → Assigned
My Deliveries
Belmont VIC 3216
Navigate with Google Maps
Proof of delivery
Photo
GPS stamped
Customer signature
Delivered 4 of 4 · Ready to invoice
Climat
Unleashed
Xero
INVOICEINV-2231
Geelong HVAC Installs
4 items · delivered in full
Issued automatically via Xero
What was shipped

Everything live & verified, grouped by who uses it

Office & dispatch
The control room
  • Jobs auto-created from Unleashed, zero manual entry
  • Drag-and-drop dispatch board
  • Day & week views for advance route planning
  • Click-to-detail cards: customer, SO#, phone, items, map
  • Inline address editing from the board
  • Ad-hoc internal jobs (not synced to Unleashed)
  • Live KPIs: Open / Unassigned / Assigned / In transit
Driver portal
On the road
  • Private, invite-only, sees only their own jobs
  • One-tap Google Maps navigation
  • Photo proof of delivery
  • Customer signature capture
  • GPS location stamped at the point of delivery
  • Partial-delivery quantity logic, per line
  • Auto Delivered date/time + “Signed By”
Integration
The plumbing
  • Bi-directional Unleashed sync, in and out
  • HMAC-SHA256 authenticated API calls
  • Invoice-safety: only full deliveries flagged Ready
  • Xero invoicing handled automatically downstream
  • Webhook receiver with replay + idempotency protection
Under the hood

The architecture

Four layers, one job: get a signed delivery to become an invoice without anyone re-typing it.

Driver
Mobile portalNative cameraSignatureGPSGoogle Maps
Climat app
Zoho CreatorDeluge logicCustom JS widget boardSortableJS
Integration
HMAC-SHA256Custom API webhookinvokeurlIdempotency + replay guard
Their systems
Unleashed (inventory)Xero (invoicing)
01

HMAC auth, by hand, from Deluge

We signed Unleashed's REST API directly from Deluge, using HMAC-SHA256 over the query string. A first-time implementation, working in production.

02

Webhook security, re-thought

Creator hides headers and re-serialises bodies, so signature checks were impossible. We pivoted to shared-secret URL auth + timestamp replay protection + unique-constraint idempotency.

03

A board that never glitches

Optimistic UI with revert-on-error, local-authoritative state to survive replica lag, delete-reconcile, 15-second polling. “Stays smooth” was a hard client constraint. Met.

04

Full-payload sync pattern

Unleashed has no partial-update and no attachment API, so we used a GET-mutate-PUT pattern and referenced POD photos as URLs inside the order's comments.

The Outcome

What changed

Live & in daily production
Confirmed running in everyday use as of 11 June 2026.
Paper-to-invoice loop, digitised
POD on the phone → status to Unleashed same day → invoice auto-flows to Xero.
Zero manual entry
Inbound auto-create proven end-to-end in a clean-room test, with no human in the loop.
Invoice disputes designed out
Partial-delivery protection blocks invoicing for goods that weren't delivered.
Your operation, next

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