New supplier, no lead-time history: how to set your first reorder dates

Your first order with the new phone-stand supplier is sitting in the app: 400 units, quoted "18 days." Shopify wants an expected arrival date, your reorder line wants a lead-time number, and you have nothing measured to give either. That gap — estimating before the first delivery lands — is its own job, and it's different from auditing a supplier you already order from, which is covered in our quoted-vs-actual lead-time guide. Here you need one defensible number today. The method below takes about twenty minutes: decompose the quote into its legs, add the legs it hides, plan the first cycle on a padded version of the total — then let the first delivery convert your estimate into data.

What a supplier's quote actually covers

Most quotes describe production time, sometimes production plus freight to the port of departure. Your planning number has to cover the whole span: order processing (PO acknowledged, deposit cleared, materials pulled), production, transit, customs, and your own receiving — unpack, count, and marked sellable. Suppliers rarely quote all five legs, and the ones they skip are precisely the ones that surprise new accounts. The full anatomy of each leg lives in the supplier lead-time guide; for a first estimate you need the shorter version: ask what the quote includes, and treat everything unmentioned as your problem.

The three anchors of a first estimate

• Anchor 1: the quote, decomposed. Ask the supplier three questions before you pay the deposit. Does the quoted time include order processing, or start when materials are pulled? Does freight go to your door, or only to the port? Are any of the components quoted in business days? The answers turn one vague number into a defined span — and a supplier who can't answer them is itself a data point.
• Anchor 2: the legs the quote omits. Whatever the quote excludes, you add yourself. Ocean freight runs in weeks and air in days; customs clearance can add several days and deserves an explicit allowance rather than optimistic silence (CBP guidance on the entry process, accessed November 2026); and receiving — your own count-and-put-away — is worth a 1–3 day planning allowance in ordinary weeks, longer in Q4 (a planning assumption to set from your own history, not a benchmark).
• Anchor 3: padding for an unproven account. New suppliers have no demonstrated reliability with you, so plan the first cycle above the estimate. A workable starting rule: add roughly 30% (an illustrative heuristic — replace it with your measured average from the second cycle onward). For a SKU you cannot afford to go bare on, plan on the padded number and hold extra buffer besides.

A worked first estimate

STAND-DK-01, a desk phone stand, sells 3.4 units/day on your trailing four-week average (illustrative numbers throughout). The new supplier quotes 18 days production, freight excluded. You choose air for the first order to keep the cycle short:

Reorder line: 3.4 × 33 = 112 units of expected demand during the wait, plus a buffer. With no lead-time history you also have no variability history, so the buffer comes from a fallback method — 10 days of demand = 34 units, using the days-of-cover fallback from safety stock without lead-time data. Trigger line = 112 + 34 = 146 units. Reorder at that line and the first cycle holds even if the supplier runs a week behind the quote — which, for an unproven account, is the outcome to survive rather than an anomaly.

Recording the first cycle so it counts

One delivery is one data point, and it only counts if you capture it completely. Four dates per PO: sent, shipped (production complete), arrived at your door, and sellable (counted and available in Shopify). Native purchase orders hold the order date, expected arrival, and receiving state (Shopify Help Center, accessed November 2026), which is enough to run the arithmetic; if your POs live in the admin, the Purchase Order Read API shipped September 17, 2026 and exposes those dates to read-only tools (shopify.dev changelog, accessed November 2026).

After the first delivery, compare the actual span against the padded plan. After three, compute a rough average and a worst case. After six to ten, you have a planning number you can defend — and from there the ongoing job becomes the audit described in the quoted-vs-actual guide. Until then, revise after every PO: if an actual span lands more than about 30% above plan (illustrative threshold), the new worst case becomes your planning number until the average catches up.

Two seasonal notes. Q4 orders queue behind everyone else's restock, so an autumn first order deserves wider padding than a spring one. And if the supplier ships from more than one factory or route, keep a number per supplier-plus-route rather than one blended figure — the reliable domestic branch and the slow overseas branch should never share an average.

Where the estimate lives once you have it

The number belongs wherever your reordering happens. InventoryX (in development) takes lead times as a manual entry per supplier — you type your planning number and the weekly Monday Buying List uses it — and nothing is auto-learned from PO history yet, so the estimate and every correction stay yours to make. When the list fires for STAND-DK-01, it reads days of cover against that 33-day span and suggests a quantity and an order-by date from it; the estimate discipline above is what keeps that suggestion trustworthy. The trigger-line math itself — how lead time and buffer combine into a reorder point — is covered in the reorder point formula walkthrough.

Common questions

How do I estimate lead time for a brand-new supplier? Decompose the quote into its legs, add the ones it leaves out, and pad the total. Ask what the quote covers (processing? freight to where?), add transit and your own receiving time, then plan the first cycle on roughly 30% above the base. After each delivery, replace the padded estimate with the measured number.

Should I use a supplier's quoted lead time as-is? Not for planning. Quotes usually cover production only — sometimes to the port of departure — and they exclude customs, inland freight, and your receiving time. Use the quote as one anchor inside a full-span estimate, and keep the padded planning number until your own PO history shows the quote is reliable.

How many orders until a lead-time estimate is trustworthy? Three orders give you a usable rough average; six to ten give you a planning number you can defend, including a worst case. Until then, keep padding the quote-based estimate and review it after every delivery. Lead times also drift seasonally, so re-check the average each quarter rather than freezing it.

What dates do I record to measure my first real lead time? Four: the day you sent the PO, the day production finished or the goods shipped, the day they arrived at your door, and the day they were counted and sellable. Lead time is the first date to the last — anything less re-creates the gap between what suppliers quote and what you experience.

Next step

Before you pay the deposit on the first order, ask the three decomposition questions and fill the leg table with your own numbers. When the goods land, record all four dates in the PO record — the workflow is in our purchase order process guide — and compare the actual span against the padded plan. That single comparison is what turns the guess into a planning number.