One Courier Is a Single Point of Failure

The phone call every seller dreads: "your carrier's pickup is suspended in your zone" — mid-sale, orders queued, no alternative. Or quieter: rates jump 20% at renewal, NDR handling fees appear, pickups slip by hours. Every one of these is survivable with a second carrier and catastrophic without one.

What concentration actually buys them

A sole carrier knows your switching cost. Negotiate rates next year and they know you can't walk — your store stops shipping while you onboard a replacement. Watch NDR rates climb and your leverage is a stern email. Their network degradation becomes your delivery promise, their fuel surcharge your margin, their festive throttle your biggest sales week. This isn't villainy; it's pricing power doing what pricing power does.

The two-carrier minimum

The rule isn't a second carrier for redundancy theatre — it's a warm backup: a live account with real weekly volume (a sixth to a fifth of your orders) so onboarding is already done, rate cards are current and service quality is measured against the same data as carrier one. A cold backup discovered in a crisis is a week of onboarding calls during your outage — a fallback that arrives too late isn't one.

The split also creates a permanent negotiation tool: quarterly, compare delivery rate, NDR handling and invoice cleanliness across both. Carriers price honestly the accounts they could lose.

The day you need a second courier is the worst day to go get one.

The bottom line

Carrier concentration trades a small efficiency for an existential dependency. Two carriers per lane — one primary, one warm — caps the downside, keeps the primary honest, and turns a network crisis into a routing decision. The cost is trivial. The alternative is a phone call you'd rather not take.