When a W-9 goes stale

A W-9 does not expire on a date the way a certificate does. It stops being reliable when the facts on it stop being true, and nothing tells you when that happens. The contractor is under no obligation to inform you, and in most cases it does not occur to them.

The four ways a form on file stops protecting you

• The payee changed entity. A sole proprietor who formed an LLC or elected corporate treatment has a different taxpayer number and a different tax classification. The old form points at neither.
• The name and number no longer match. If the IRS tells you the combination does not match its records, you are on notice, and continuing to pay without withholding is a decision rather than an oversight.
• The form was never complete. A signature block left blank, a classification not ticked, a number that is nine digits of something else. A form that would not survive being looked at is not a form.
• You cannot find it. This is the most common one and the least discussed. A form nobody can produce on the day it is asked for is functionally missing.

Requested is not received

The state that causes the most trouble is the one in the middle: you asked, they said yes, nothing arrived, and the payee sits in your records as though the matter is handled. WithholdWatch keeps missing, requested, valid, expired, TIN mismatch and refused as six separate states, because they call for six different actions and collapsing them into “has a form / does not” is how a payee gets forgotten for a year.

A practical cadence

Re-request a form when a payee tells you anything has changed, when a name on an invoice stops matching the name on the form, and at the start of any year in which you expect to pay someone materially more than last year. Re-requesting costs an email. The alternative costs a percentage of everything you paid them after they crossed.