What is a vendor master file?

Definition

A vendor master file is the standing record of a supplier in your books. It holds the legal name, tax ID, addresses, payment terms, and bank details the business uses whenever that supplier is billed or paid.

It is a setup record, not a balance. Nothing sits on the Balance Sheet just because the card exists.

Where it shows up

Balance Sheet: Related to nothing extra until a later bill posts to that vendor.

P&L: Related to nothing extra.

Cash flow: Related to nothing extra until a later payment uses those bank details.

See also: Vendor Onboarding · Accounts Payable · Form W-9

When you look at the Balance Sheet, you will not find a line named for this record. The card lives in the payables system behind accounts payable.

The Income Statement also stays quiet at this step. Expense shows up later, when a bill is recorded against that vendor.

Cash does not move when you save the card. Cash leaves only when a later payment uses the bank details stored there.

In the payables app, this is the vendor card you open before you enter a bill. Name, terms, and payment method all come from that card so later documents stay consistent.

How it works

Someone collects the vendor's legal name, mailing address, and tax ID before the first payment. Those facts go on the vendor card so later bills and payments all point to the same supplier.

Payment terms go on the card next. Net 15, net 30, or due on receipt then apply to every later invoice unless a single bill overrides them.

Bank details go on last if you pay by ACH payment or wire transfer. The card is what the next check run reads, so a wrong account number sends cash to the wrong place.

Who can edit the card matters. One person should not both change bank details and approve the payment that uses them.

A duplicate card is a common failure. Two records for the same bakery split the history and hide what you already owe.

Form W-9 support sits on the same card. The tax ID from that form is what year-end information returns later need.

Inactive vendors stay on file rather than being erased. You stop new bills against them, but you keep the history so old payments still make sense.

The card also stores how the vendor wants to be paid and where remittances should go. Get those fields right once, and every later payment follows the same path.

Example

A cafe starts buying bread from a neighborhood bakery. Before the first loaf is ordered, the owner opens a vendor card and stores the bakery's legal name, Form W-9, net-15 terms, and the checking account the bakery wants used for ACH.

The card itself posts nothing. No debit, no credit, and no new payable appears.

The next week the bakery bills $1,200 for loaves. That bill posts to the bakery's vendor card, and accounts payable goes up by $1,200.

When Friday's check run pays the bakery, the system pulls the stored bank details and terms from the same card. Cash leaves, the payable clears, and the cafe does not retype the routing number each time.

If someone later edits the bakery's bank account, every future payment follows the new details. That is why changes to the master file need a second pair of eyes.

Six months later a new baker asks to be paid on net 30. The cafe updates terms on that one card, and later bills pick up net 30 without a new setup.

At year end the tax ID on the same card is what the cafe uses to decide whether an information return is due. The card did not create the spend, but it kept the facts the filing needs.

Common mix-ups

The vendor master file is not the bill. The card names the supplier; the bill is the later document that creates the payable.

The vendor master file is not the same as the payables balance. Accounts payable is what you owe; the master file is the address book those amounts attach to.

A W-9 is not the vendor card. Form W-9 is the tax form you collect, and the card is where you store what that form told you plus terms and bank details the form never asked for.

Related terms

• Vendor Onboarding: The steps for setting up a new supplier before the first payment.
• Form W-9: The form collected from a vendor to capture its taxpayer identification details.
• Accounts Payable: Amounts the business owes vendors for goods or services already received.
• Vendor Bill: The invoice a supplier sends that becomes a payable.
• Internal Controls: The procedures that keep the books accurate and assets protected.
• Payment Terms: The agreed deadline and conditions for paying an invoice.
• Segregation Of Duties: Splitting recording, approving, and payment tasks so no one person controls a transaction end to end.
• Purchase Order: The document authorizing a purchase from a vendor at agreed terms.