All items that you carry in your purse when boarding a plane will be subject to security screening and most items you normally carry will pass through with no problem. The main categories of excluded item are sharp, large, explosive or otherwise dangerous objects, as well as many types of liquids and gels.

Commonly Carried Items

Your wallet, money, and keys may set off the metal detector at the security checkpoint, but it's fine to carry them in your purse. Other personal and comfort items like prescription and over-the-counter medications including liquids, tissues, manicure items and a sewing kit are also fine. However, no pointed or sharp knives of any kind may be carried on the plane, including pocket knives, multi-tools with knives and craft or utility knives.

Electronics

You can carry your mobile phone or other small electronic devices in your purse, however they will need to be turned off completely during takeoff and landing. Calling and using cellular Internet applications are also prohibited for the whole flight.

Lighters

Although most flammable substances are restricted, you can carry standard lighters in your purse. You may also have one book of safety matches.

Toiletries

Most toiletries and cosmetics are fine to carry in your purse, but larger containers or liquids and gels are restricted in all bags carried on the plane. No individual container of any liquid or gel product larger than 3.4 ounces is permitted.

Food

Food is a great thing to have in your purse for a flight, but keep in mind that the fluid and gel restrictions do apply to food and drinks, also. Most foods will be fine, but skipping the yogurt is probably a good idea. Since drinks are almost always larger than the permitted size, your best bet is probably to buy extra drinks in the airport, past the security checkpoint. It's fine to carry these pre-screened drinks onboard.

There is an exception to the size limit for passengers traveling with babies, who may carry larger containers of liquid and gel foods through security.

Gifts

You may carry wrapped gifts in your purse, but it is possible that they will need to be unwrapped and inspected at the security checkpoint. TSA recommends that passengers wrap gifts after arriving, or transport them in another way.