Depending on when you make your travel plans, you may not be getting the best deal possible—no matter how carefully you try to time it. Prices for hotels go up and down constantly, so that room you booked for $150 in February might be available for just $90 in May, even if the travel dates are the same. Pruvo wants to help make sure you never miss out on one of these lower prices. According to Lonely Planet, the free service will monitor your reservation to see if you can get a better deal on the same type of room on the same dates.

All you need to do is forward your confirmation email from the hotel to Pruvo's inbox (save@pruvo.net) and the service will begin to monitor the price of that reservation. The only catch is that your original reservation must offer free cancellation—otherwise you won't be able to cancel and rebook without losing money.

If Pruvo does see a price drop at some point before your trip, you'll get an email alerting you to rebook your reservation to save money and a suggestion for which booking site will provide a cheaper option. While Pruvo won't do the rebooking for you, that also means that you don't have to give the service your credit card details, and you get to keep the full amount of your savings.

According to Pruvo, almost 40 percent of hotels dropped their prices at some point during 2016, leading 14 million travelers to overpay for their stays that year. The company told Lonely Planet that it has found its clients better deals on two out of five reservations prior to check-in.

Pruvo isn't the only service that aims to help customers avoid losing out when travel prices drop. DoNotPay, a robot lawyer service, uses artificial intelligence to search the web for cheaper prices on both flights and hotels you've booked, but you don't have to do the rebooking yourself—it negotiates with the company to get you the cheaper price or rebooks the reservation for you. (The site also features a similar service to challenge parking tickets.)

We all know travel can be expensive, so there's no reason to pay any more for your trip than you have to—especially if someone else will do the legwork for you.

[h/t Lonely Planet]