Updated April 2026 · Save Up to 7% on your rental
Contract ID Number
Yes, National routinely audits American Express Affinity Contract ID usage. You should be prepared to present a valid employee badge, corporate email verification, or business card at the rental counter. Failure to provide ID may result in your reservation reverting to the standard walk-up rate.
The American Express Affinity Contract ID (5066944) is primarily intended for business travel. While some corporate codes allow leisure use, National agents may request proof of employment. For leisure travel without ID checks, consider using public promotional codes or our AI-recommended alternatives.
The National Contract ID for American Express Affinity is 5066944. This code provides 10-25% discount on car rentals. Enter this code in the Contract ID field during checkout at National.com or present it at the counter.