If you often travel internationally, professionally or as a tourist, your passport is probably filling up with visa stamps. A standard booklet contains 24 blank visa pages. If most of these have been filled you should consider adding pages to your US online passport. This can be done through a simple application process to the State Department.

If the booklet or second valid United States passport is completely full, this process is necessary for any further travel. However, it is wise to preempt this situation by applying for additional space when you're down to only a few blank spaces. Some countries require two or more empty pages for the visa process, so a nearly full booklet could lead to you being fined and sent home at your own expense.

Applications for additional pages should be sent to the Department of State, which is responsible for travel documents and visas. To apply, you must have a passport that is valid for at least one more year. If this is not applicable to you, you should instead submit to be issued with a passport or to have one renewed.

This service is regularly required by those who travel often and the process is not complicated. Mail the passport and a DS-4085 form to the address cited on the form. As of July 2011, the service costs $82 dollars with an additional fee for the expedited service. These fees are payable by mail via check or money order and at a local passport agency or acceptance facility you may be allowed to pay using cash or credit card.

In the event that forms are incomplete or incorrectly filled out, the application will not be processed and the fee will still be charged. For your own convenience, ensure that the application is completely and correctly submitted. It is also strongly recommended that you use secure, traceable methods of delivery and packaging for the safety of valuable documents. Allow ample time before you next plan to travel, as at the standard rate this amendment takes four to six weeks.

If travelers require their passports returned more quickly, there is a faster but costlier procedure available. This expedited service costs an additional $60. On top of that, the recommended overnight delivery service costs $12.72. To speed up processing time, pay these additional costs and clearly mark 'Expedite' on the outside of the mailing envelope. From door to door, this service will take two to three weeks.

For those who need the quickest service available, it is possible to make an appointment with a local agency. This service is only available if the person is travelling internationally within two weeks or applying for a visa within four weeks. You will generally be required to present proof of travel, such as a travel itinerary, in order to make an appointment.

If you are thinking of adding pages to your U S online passport or your second valid passport, take the time to fully understand the application process and choose the option best suited for you. If you know the requirements and allow enough time for your chosen service, the application process is straightforward and you'll have your 48-page booklet returned to you for your next trip.