The standard contract provides for 30 days payment terms.
Advertisers who try to push payment beyond 30 days are creating operational problems for their agency.
Agencies’ costs are predominantly staff (paid monthly) and rent (paid quarterly in advance). Production companies producing TV commercials are entitled to bill creative agencies 50% prior to production to assist the cashflow for what are typically small boutique operations.
For media buying agencies, it is essential they collect payment for media space prior to settling with media owners. Media owners typically require payment in the month following appearance.