Mainfreight + ReturnMate

Mainfreight is one of the few carriers that handles both Australian and New Zealand domestic freight from a single API, with dangerous-goods capability across both markets. Useful for trans-Tasman merchants and any AU operation that outgrows AusPost size limits or needs a depot drop-off network outside the AusPost / Australia Post Group.

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§ 01 — Capabilities

What the Mainfreight connection actually does.

REST API integration covering shipments, rates, labels, and tracking
AU and NZ domestic freight from one account
Dangerous-goods support across both markets
Multi-item consignments with consolidated tracking number
Live rate quoting for the customer portal
Tracking webhooks plus polling fallback for partial coverage areas

§ 02 — In practice

Where it earns its place.

Trans-Tasman returns

AU customer ships back to a NZ warehouse (or vice versa) on a single Mainfreight consignment without needing two carriers and two label generations. Customs documentation surfaces in the same record.

Heavy non-DG freight beyond AusPost limits

For RMAs with parcels over 22kg or 1.05m on any side, AusPost won't accept the booking. Mainfreight does, with the same branded-label experience and tracking surface.

DG returns under or over 22kg

Unlike AusPost (no DG) or StarTrack (DG up to 22kg), Mainfreight handles DG shipments at any weight. ReturnMate routes automatically based on the SKU's DG flag and weight.

§ 03 — Setup

How Mainfreight gets connected.

Carrier accounts are set up by our team, not by you. We contact Mainfreight directly, obtain API access against your existing commercial account, and apply it — so you never have to source or handle API credentials.

You send us three things
Your existing Mainfreight account number, written authority for ReturnMate to contact them on your behalf, and your account manager's name, email and phone number.
We contact Mainfreight
Our support team requests API access against your account and handles the paperwork and technical back-and-forth with the carrier.
We apply the credentials
Credentials are stored encrypted against your shop. They are never shown to you and never need to be — there is nothing for you to paste or maintain.
We test it end to end
We generate a test label — including the dangerous goods transport document where it applies — and confirm it works before the carrier goes live for your team.

Turnaround varies by carrier, depending on how quickly they issue API access. Support confirms the expected timeline for Mainfreight when you start onboarding. Don't have an account with them yet? We can help you set one up.

§ FAQ

Questions about Mainfreight.

Does Mainfreight handle dangerous goods in both AU and NZ?

Yes. Mainfreight is one of the few carriers that supports DG shipments across both Australian (ADG) and New Zealand (Land Transport Rule) compliance frameworks from a single account. ReturnMate generates the appropriate transport documents for whichever market the shipment originates in.

When should I pick Mainfreight over AusPost or TGE?

Three cases: (1) the parcel is over AusPost's size or weight limits (22kg / 1.05m), (2) you need DG capability without the StarTrack 22kg cap, or (3) you operate trans-Tasman and want a single-carrier story. For domestic AU non-DG under 22kg, AusPost is usually cheaper.

How does Mainfreight tracking compare to AusPost or NZ Post?

Mainfreight's tracking is consignment-level rather than parcel-level — useful for multi-item shipments where you want one tracking ID for the whole RMA. Event granularity is comparable to AusPost; less frequent than express services like TNT.

§ Enquire

Ask about the Mainfreight integration.

Tell us how you ship with Mainfreight

Volumes, lanes, whether you already have an account — we'll come back within one business day.

§ Related

Often set up together.

Carriers

Wire your stack together.

Start free — 5 returns a month on the Free plan, no credit card required. Billed through Shopify.

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