Issue:

You might see a serial number error while trying to activate a product for one of several reasons:

Typos during activation
Serial number doesn't match the product
Serial number isn't valid anymore
Contact information isn't associated with this serial number
Activation limit exceeded for this license

Solution:

Typos made during activation
Take care entering these values as you register and activate your products, so that you don’t inadvertently transpose or skip numbers or letters.

• Serial Number is misspelled
  - Serial Number must have exactly 12 characters (11 numerals and a hyphen)
  - Serial Number cannot contain alpha characters
  See:Finding Serial Numbers & Product Keys
• Company name must match the account name listed for the license
• Host Name is incorrect (only valid for Network Licenses)
• Machine address, Physical Address, or Host ID is incorrect (only valid for Network Licenses)
• Host ID is incorrect (only valid for Network Licenses
  See:How to find your Host Name and Physical Address

Serial Number does not match the product
This error is often displayed as 'Serial Number is invalid.'
There are several reasons why this mismatch can occur.

• The serial number is valid, but is associated with a different product (e.g., AutoCAD LT 2010 versus AutoCAD 2010)
• The serial number is valid, but is associated with a different version of AutoCAD (e.g., AutoCAD 2009 versus AutoCAD 2011)
• The serial number is valid for a network deployment, but you are trying to activate the product as a standalone license (and vice versa)

Before registering and activating your license, be sure the Serial Number you are using matches the product and release of the product and the type of license you have purchased. You can request a report that lists information about your product serial numbers, including product, version, and status, by visiting Contact Support - License Reports.

Serial number is not valid anymore
There are a number of reasons why a serial number may not be valid.

• Your product might have been upgraded to a new version or cross-graded to a different product
• The serial number is associated with a product or a release of a product that you are not licensed to use
• The serial number is obsolete and has been replaced with another serial number in an effort to simplify a Subscription contract

Before registering and activating your product, be sure the Serial Number you are using matches the product, product release, and the type of license you have purchased.
See:

If you are activating a product in a Suite:
Be sure to use the serial number and product key for the Suite (not the individual product) to activate your products.
See: Finding Serial Numbers & Product Keys

Contact information does not match what is already associated with the Serial Number when the product was registered
This usually occurs when there is a change to your name, the name of your company, or your address after the product was registered. Be sure to keep your contact information up to date in Register Once. There, you can add an account with your current information, register products to that account, and delete your old accounts, or those with outdated information.

Activation limit exceeded for the license
Activation limits are set based on the type of license agreement you have with Autodesk. They are designed so that you can easily remain compliant with the license you purchased and so that you are protected from someone else using your license. (You may receive 'Error 10: Activation Limit Reached' during the in-product activation process.)

• If you have a standalone license, you might be able to transfer a license to activate this product. See: Using the License Transfer Utility to Transfer Licenses Online

  Otherwise, visit AVA (Autodesk Virtual Agent) to resolve the issue and automatically receive an Activation Code or connect with an agent. Be sure to provide your serial number, request code, and contact information

• If you have a network license, contact Customer Support.

See Also: