You may start the process online or come in and register in person. Both methods require a photo ID/proof of Plainsboro address.

• Plainsboro residents: Bring your photo ID and proof of a current Plainsboro address to the library to apply for your card. This can be a single item (example: an up-to-date license) or two separate documents (example: passport and lease agreement). You may also click here to begin the application process, and then bring your temporary number along with your photo ID/proof of address to the library to complete your application and pick up your card.
  
• Applicable Mercer county residents (list of applicable Mercer towns): You must have a valid library account at your home library in good standing. Bring that Mercer library card along with photo ID and proof of address to the Plainsboro library to receive reciprocal privileges here, which will give you access to check out any item in the building.

Your application will be sent a temporary number that will be used to save your information until your registration is completed.
This number is not your new card number. It is a placeholder for your card application. It will not give you access to online resources until in-person registration has been completed