When most parents start making a wish list of all the qualities their ideal nanny will have, there’s one common thing that appears near the top of almost every list: a nanny who doesn’t spend the whole day looking at her cell phone. Cell phones are a fact of life. We all have one, and we all rely on our phones to keep us connected to our loved ones, employers, and everything going on in the world, but when you’re a nanny, the children have to be your number one priority at all times—even when it means having missed calls and texts.

It shouldn’t surprise you to find out that cell phone use is one of the biggest factors in trial days that go awry. It’s also the main reason that nannies get fired. It’s not that anyone expects you to forego having a phone or to neglect your personal life. It’s just that when a nanny is busy on the phone, the children aren’t being engaged, and that means the nanny isn’t performing the core duties of her job. You’d be totally annoyed if your doctor was scrolling through Facebook while listening to you describe your symptoms, or if your barista made you wait to order your latte so she could finish texting her bestie. Looking at your phone while you’re supposed to be caring for someone’s children is no different.

That said, it’s unreasonable to think that a nanny will never, ever look at her phone. After all, cell phones are how most parents get in touch with their nannies and give them important updates and information about the children. But, as in any professional setting, the time for calls and checking for new messages needs to be carefully managed so you’re always “on” when you need to be and parents know that your job and their children are your number one priority. The best way to do this is to make a plan for your day and communicate with parents about their expectations.

As soon as you get to work, ditch the phone.

Ideally, you should arrive at work focused and ready to go, with your phone already put away. When you’re on the clock, the phone should be stashed in a purse or some other safe place where you won’t be tempted to look at it all the time. You can leave the ringer on and set a special ring tone for the children’s parents so you know if you’re getting an important call that needs to be answered. If you have mileage or expense apps that need to be updated, set aside time to do that later in the day. Similarly, if you need to check on times for activities or look at a schedule, try to do that before work so you’re walking in already prepared for the day ahead.

Designate specific times for checking messages.

Parents use cell phones to communicate with you. That’s just a fact. But that doesn’t mean you need to be watching the phone every second just in case they text or call. You could plan to check the phone briefly at snack time and/or during children’s naps. Even then, you should think of it as a quick check-in to see if you have an texts or calls from the children’s mom or dad. Work simply isn’t the place to scroll through the latest Instagram posts and see what’s up on Twitter. Nap time, in particular, is a great time to get caught up on tidying, fold laundry, and plan activities for the rest of the day, so you shouldn’t waste that valuable time on the phone.

Talk to parents about their expectations and your plan.

The best way to know how parents feel about cell phone use is to ask. Some might provided a phone for you, and some might reimburse you for any time you have to use your own phone during working hours, but either way, it’s important for you to know what their expectations are for how often you should be on the phone and what’s considered appropriate during working hours. You might say something like, “I’m planning to keep my phone in my purse, but I will leave the ringer on in case you need to call, and I’ll briefly check to see if I have any messages from you when the children go down for a nap. Does that work for you?”

That lets parents know that you’re always reachable but will ultimately be focusing on your time with the children. Some families may be more lax about cell phones or expect you to be available more frequently for texts and calls. That’s okay, too. The important thing is that you are thinking through your cell phone use in a professional way and always communicating with parents so they know they can count on you to be present with their children.