Supplier due diligence checklist: 10 checks before you place an order

The short answer

Supplier due diligence means verifying that a supplier is who they say they are, can make what you need to the standard you need, and operates legally and ethically. Run the ten checks below before any production order, record what you found, and repeat the key checks every year.

Why due diligence matters

A new supplier is a risk to your cash, your delivery dates and your reputation. Most failures, from quality problems to outright fraud, show warning signs that a structured check would have caught. Due diligence also gives you a documented record if a customer, insurer or regulator ever asks how you chose your supply chain.

The 10-point checklist

1. 1.Legal identity. Confirm the company registration, registered address and directors, and make sure the entity on your contract and invoice is the same one you vetted.
2. 2.Bank details. Verify payment details by phone using a number you sourced independently. Be wary of any late request to change bank accounts.
3. 3.Financial stability. Look at trading history, size and, where available, filed accounts. A supplier in financial difficulty may cut corners or fail mid-order.
4. 4.Production capability. Confirm the factory owns the equipment and has the capacity to make your volume alongside its existing customers.
5. 5.Quality systems. Ask how quality is controlled at each stage. Certifications such as ISO 9001 are useful evidence, but check they are current and genuine.
6. 6.Product compliance. Request test reports for the standards your product must meet in the UK, and confirm the test laboratory is accredited.
7. 7.References. Speak to at least two current customers, ideally in comparable markets.
8. 8.Ethical and labour standards. Ask about working hours, wages, subcontracting and any social audits. Unauthorised subcontracting is a common hidden risk.
9. 9.Intellectual property. Agree in writing who owns your designs and moulds, and what the supplier may not do with them.
10. 10.Site verification. Visit, or commission an independent audit, to confirm everything above in person.

What are the biggest red flags?

• Pressure to pay the full amount upfront or to an individual's account
• Reluctance to share a business licence or allow a visit
• Prices far below every other qualified quote
• Samples that look noticeably better than anything the factory can show on its own lines
• Vague answers about who actually manufactures the goods

Keep it proportionate

Not every supplier needs the same depth of review. A low-value, low-risk component may need only the first few checks. A supplier making a regulated product sold under your brand needs all ten, plus ongoing monitoring. Grade suppliers by risk and spend, and set your checks accordingly.

Make it a process, not a one-off

Store the evidence for each supplier in one place, note the date of each check and set a reminder to review it. Re-check when anything material changes, such as new ownership, a new factory site or a sudden change in quality. If you are still building your shortlist, start with our guide on how to find a reliable manufacturer overseas.

Frequently asked questions

How long does supplier due diligence take?

Desk-based checks can be completed in days. Allow longer if you need samples, test reports or a site audit, as these depend on the supplier's schedule.

Can I do due diligence without visiting the supplier?

You can complete most desk checks remotely, and video tours help. For important suppliers, an in-person visit or independent audit remains the most reliable way to confirm capability and working conditions.

How often should suppliers be re-checked?

Review key suppliers at least once a year, and immediately after any significant change in ownership, location or performance.

Want a second pair of eyes on a supplier?

We carry out practical supplier checks for UK buyers and manufacturers. Get in touch to discuss what you need verified.