Supplier Onboarding Checklist: Documents, Checks, Approval

Why supplier onboarding matters

Supplier onboarding is the set of steps between deciding to buy from someone new and placing the first order or making the first payment, and it is where most supplier record mistakes begin.

Every supplier in your accounting system started as a name someone typed in. If that record has the wrong tax number, a misspelled company name or bank details nobody confirmed, the mistake travels with every bill and every payment that follows. Fixing it later means finding every entry it touched.

Good onboarding also protects you against fraud. A request to pay a "new" supplier, or an email saying an existing supplier has changed bank, is one of the most common ways businesses lose money. A routine that checks documents and confirms bank details before anyone pays turns that risk into a step on a list.

Some people call it vendor onboarding; the work is the same. You decide what a new supplier must send, you collect it, you check it, the record is approved, and only then does the supplier become available for orders and bills. This guide sets out each stage of supplier onboarding as a checklist you can adapt to your own business, from the first request to the approved record.

The document checklist

The core supplier onboarding documents are the legal company details, the tax registration, the bank details on the supplier's own paper, a named contact and any certificates your trade requires.

What you ask for depends on what you buy and where the supplier is based. A food business will want hygiene and allergen documents; a construction firm will want insurance cover; a business buying across borders will want the supplier's tax registration in the form its own country uses. Requirements vary by country and sector, so check the list with your adviser before you fix it.

The table is a starting point: what to request, why, and what to look at when it arrives.

Checking: missing, expired, mismatched

Every document that arrives should pass three checks: is anything missing, has anything expired, and does anything disagree with the rest.

Missing documents are the easiest to see and the easiest to forget about. A supplier sends four of six items, an order is urgent, and the record is created anyway with a note to chase the rest. A month later nobody remembers the note. A register with one column per document, marked received or not, keeps the gap visible.

Expired documents are quieter, and they are the gap most supplier onboarding routines leave open. An insurance certificate valid at onboarding may lapse within the year, and nobody looks again until there is a claim. Recording the expiry date of each certificate, and asking for a fresh copy before it runs out, is what keeps the file honest.

Mismatches are the most important to catch, because they are often the first sign of a mistake or a fraud. In supplier onboarding, look for these in particular:

• The company name on the registration differs from the name on the invoice or the bank letter.
• The bank account name does not match the supplier's legal name.
• The contact's email domain differs from the company's website or letterhead.
• The tax number on the invoice differs from the one on the registration.
• The address on the certificates differs from the registered address without explanation.
• A document is clearly a copy of another supplier's paper with details changed.

Bank details and fraud checks

Confirm new or changed bank details by phone, on a number you already hold for the supplier, before any payment is made.

Email alone is not enough. Mailboxes are compromised, look-alike domains are cheap, and a convincing letter on headed paper takes minutes to fake. The check that works is a call to a number you found independently, such as one from an earlier invoice or the supplier's public website, never the number printed on the letter that announces the change.

The same routine applies when an existing supplier says its bank has changed. Treat that message as a fresh round of supplier onboarding: stop payments to the new details until the check is done. It is the step people are most tempted to skip when a supplier is familiar and the request looks routine, and it is precisely the case a fraudster relies on. A short routine looks like this.

1. Receive the bank details on the supplier's own letterhead or bank letter, not typed into the body of an email.
2. Compare the account name with the supplier's legal name from the registration document.
3. Call the supplier on a number you already hold, not one taken from the new letter, and read the details back.
4. Record who confirmed them, on what date and from which number, in the supplier register.
5. Have a second person approve the bank details before the record is used for any payment.
6. Make the first payment small or routine where you can, and confirm with the supplier that it arrived.

Approval and the supplier register

A new supplier should exist in your accounting system only after a named person has approved it, and a register should show what was checked and when.

The register is the memory of your supplier onboarding: a simple sheet with one row per supplier. Columns typically cover the legal name, tax number, contact, each required document marked received with its date, each certificate's expiry date, how the bank details were confirmed, who approved the supplier and when. It answers the auditor's question and the colleague's question in the same place.

This is how our supplier bills robot works today for a client: when a bill arrives from a supplier it has never seen, it does not create the supplier. It passes the bill to a person, and the new supplier is created only after the owner approves it. Until then the bill waits. The same principle applies to the whole onboarding process: the robot can gather and check, but only a person says yes. Keeping the approval separate from the person who asked for the supplier is a simple control, and it costs a few minutes per new supplier.

Automating the chase

The part of supplier onboarding worth automating is the chasing: requesting documents, noticing what has arrived, flagging what is missing or expiring and filing everything in one place.

That is the onboarding AI employee we offer, built to order on the same engine as the bills robot that is running today. When a new supplier is agreed, it prepares a draft email requesting your list of documents. As replies arrive, it reads the attachments, marks each document received on the register, notes expiry dates, flags mismatches and files the papers in the supplier's folder. When something is still missing after a set time, it prepares a draft reminder. Every email waits as a draft in your own mailbox, and the record is complete before the approval step.

The same routine works the other way round. Client onboarding automation follows the customer onboarding process you already have: the documents a new client must provide, such as company details, tax numbers and signed terms, requested, collected and checked in the same way. Our online contract signing, running today, can carry the signed terms.

It runs on our servers against your own mailbox, folders and sheets, and it is rented monthly, priced per workflow in the quote. It does not verify identities against official registers on its own, it does not give legal or compliance advice, and it does not phone anyone: the call to confirm bank details stays with a person. Check your own requirements with your adviser.

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