The responsibilities of a seamstress depend on which category of the profession to which she belongs. The types, or categories, are named for her counterpart, the tailor, and include local tailoring, distance tailoring and traveling tailoring.

Local tailors and seamstresses, as the name indicates, serve their local community with sewing services. Typically, they work in a small independent shop, where customers come in to purchase custom tailored clothes or have garments repaired. With local tailoring, seamstresses are able to take measurements of their clients to ensure the final product will fit perfectly. They not only assess measurements, but the client's posture and body type as well. Usually these shops will have a front showroom where customers can also browse through fabrics and sample work from the seamstress. Local tailoring allows clients to easily return garments for alterations and serves the local community with repair services. In some cases, local shops with the right clientele and reputation have achieved worldwide recognition. Most seamstresses will work in this type of environment.

Distance tailors and seamstresses offer their services to out-of-town customers. Typically, there is no store front because most sales are made through the Internet. Services from distance tailors are often much cheaper because inexpensive labor can be obtained, there is less overhead in maintaining a storefront, and customers are responsible for taking their own measurements. Services to the client, however, are also reduced since customers are often limited to viewing photos for their fabric selections and must return garments by mail for alterations, prolonging the process. Online tailoring is becoming much more common due to the easy accessibility and widespread presence of the internet. Experienced seamstresses can set up their own online storefronts and offer their services to customers around the world.

The less common traveling tailors and seamstresses are a mix of both distance tailoring and local tailoring. These seamstresses operate in a local or regional area, but travel to accommodate clients' needs. They usually have a travel case, with all the tools for taking measurements of their clients, along with a book or packet of sample fabrics for the client to peruse. This limits the problems associated with distance or online tailoring in the initial assessment phase, but clients will still receive the final product by mail. Additionally, if any alterations are necessary, they must ship the garment back to the seamstress. She must then make her best assessment of where the garment should be altered before sending it back to the client.

Whatever the type they choose to be, seamstresses must fulfill several core responsibilities. They must alter or repair garments according to their customers' specifications, be able to operate a variety of sewing equipment and interact professionally with their clients. In addition, they may be responsible for tagging or marking garments and keeping accurate records of supplies used in each creation. Sometimes, seamstresses may be given creative or artistic challenges by the client, which might include a dress that is appropriate for both home or garden wear or a suit that's breathable in the summer but can adapt to cold weather climates.