Using your sides during an audition is a debate I have had with many Actors.  Some believe holding your sides during an audition tells casting and the decision makers (directors, writers, producers, and showrunners) that what you are showing is an unfinished performance and that once hired the performance will be even better on set. Not holding your sides conveys that your performance is showing a finished product. What you see is what you get. The performance is locked and can't and won't be adjusted.  

So, should you hold them or shouldn't you? I believe the answer is... it depends.

If you are auditioning for a one-line co-star, I don't believe it is in the Actor's best interest to hold their sides. I would recommend that the Actor take the time to memorize the line, actions in the scene, and rehearse until they feel confident in demonstrating what is expected of the character.

If you have one line, you should be able to recite it with ease. The decision makers will be thinking the same thing and I believe will be focused on why a "professional" Actor is holding their sides when they could be delivering a performance that is as close to a representation of what it will be like on set. 

For one-line co-star parts, the Actor is being hired to deliver a performance that is locked, loaded, and will never fail. These parts are serving the leads of the show. Rarely will there be much time spent adjusting a performance that is usually required to deliver exposition, a reaction, or information that moves the plot forward. That time will be spent on the larger co-star roles, guest stars, and leads of the show.

For larger scenes (Series Reg, Guest Stars, and Larger Co-Stars)  I think you can hold your sides and even use them as a prop in the scene if it's necessary. The decision makers know that your audition isn't your final performance. They know that Actors often have little time to prepare the scene. They are not distracted by you, the actor, holding your sides. When applicable you can even use your sides as a prop. For example, if your character is handling files in your scene, incorporate your sides as the files. 

But beware... When you don't hold your sides you might forget a line and ruin a take. Is it the end of the world? No. But, it is an icky feeling to have to start again and could disrupt your confidence. But, if you are prepared and fail gracefully, I am sure the Casting Director will be supportive and let you go again. If you forget a line again and have to stop I would recommend pulling your sides out and holding them. If this happens... this is a good learning experience. Don't beat yourself up, it happens to everyone.

When people ask questions like: should I hold my sides, should I use a prop, should I enter, should I look left, etc. The answer to all is: what action is going to provide you, the Actor, with the most truthful performance?

I personally strive to deliver all of my auditions large or small being totally memorized and I will only hold my sides IF I am incorporating them as a prop.

What do you do?