If you travel frequently, whether for work or pleasure, you are likely to have to consider adding pages to your US online passport. A standard booklet has 24 visa sheets. If these are filled with visa stamps the document is no longer usable so must be submitted to the State Department to have another 24 visa pages added.

If the booklet or second valid online 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.

When applying, be sure that this is the State Department service you require. To qualify for additional pages, you must be in possession of a valid passport with an expiry date more than one year away. If this does not apply, a different service is probably required such as having travel documents issued or renewed.

The application process is quite straightforward. You must submit the booklet and a completed application form by mail to the State Department. The standard service comes at a cost of $82 with an additional fee if you are in a hurry to get your extra space. Payment can be made by mail using personal checks or money orders. At a passport agency or an acceptance facility, credit cards and (in some cases) cash can be used to pay processing fees.

The department requires that forms be correctly and completely filled out. If there is a fault with an application, it will not be processed and fees will not be refunded. Take care to submit a complete application to save yourself any trouble. Additionally, when sending valuable documents it is advisable to use a traceable delivery method and secure, weatherproof packaging. The booklet will be returned in 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 urgently require additional visa space, appointments are available with local passport agencies. However, to grant an appointment most agencies will require a travel itinerary, to establish that the holder is travelling internationally within two weeks or applying for a visa within four weeks.

This is an often-used service if you are adding pages to your U.S. online passport or your second valid United States passport because, whether for personal or professional reasons, you travel very regularly and accumulate large numbers of visa stamps. The process doesn't have to be overly inconvenient or complicated. Pay attention to the application, know the different options available to you and take the appropriate precautions and you'll soon have your passport back and be ready to continue travelling.