Read the small print on websites when booking tickets online, as there are strings attached to many of the deals that you can only discover with a meticulous review of the terms and conditions.

Travel websites have changed a lot about vacation planning. You can see options you didn’t know existed, read user reviews to get a feel for whether a place is right for you, and — best of all — you can often get legitimate discounts by booking online.

But as internet-using road warriors are discovering, there are strings attached to many of the deals that you can only discover with a meticulous review of the fine print.

Just ask Toronto photographer John Hryniuk, who thought he had a great deal when he booked a vacation flight to Zurich online on Travelocity.ca.

"It was an Air Canada flight to Zurich," he said. "The flight cost $1,000, not much of a discount, but I was in a rush and thought the website would give me the best price at the last minute. Later, I found out it was only slightly lower than the price on Air Canada’s site."

And only after the trip was over did he find that his ticket didn't qualify for any air miles.

Some airlines give customers travel points if they book through discount ticket brokers, others don't.

"I complained to Aeroplan and was rudely told that it was because I had bought my ticket on Travelocity," he says. "A lot of the time tickets purchased on that site and many others don't qualify for frequent flyer miles."

But Hryniuk's chances of discovering that fact from anything on the website would be slim. Air-mile qualification is not one of the frequently asked questions on Travelocity’s help menu, and only by trial and error can you find the key word "points" that brings this explanation: "The fare rules (available during the booking process) of the ticket you purchased will need to be reviewed to determine if the fare type you booked qualifies for frequent flyer mileage."

If the flight were booked with a travel agent or over the phone to Air Canada, Hryniuk would have found Aeroplan gives no miles for discount flights in several tourist-class categories. But there is no mention of that when you book online.

Read the fine print

And those aren’t the only hidden costs and caveats of booking your own travel online.

I found that out the hard way recently only after I had given my credit card number and booked a two-night hotel stay in Rome on Hotels.ca, a division of Expedia. The receipt showed that in addition to the $718 for the stay, there was a whopping $82.58 tacked on for "tax recovery charges and fees."

That extra charge had only been revealed in tiny type at the lower corner of the screen, separate from the total that appeared when the booking was being processed. And you had to go three-quarters of the way through pages of fine print on a separate page, called "Terms of use," to find this explanation: "Our service fee varies based on the amount and location of your reservation." And it added: "Taxability and the appropriate tax rate vary greatly by location."

Calling the hotel directly, I found I could have booked the rooms at the same price without the service charge. By booking by phone instead of online, I would also not have been subject to the website’s $26 service charge if I had to cancel the reservation. And I wouldn’t have had the cost of the room billed to my credit card until the end of my stay.

So book online if you find it convenient, but keep these suggestions in mind:

Read the fine print: Be aware that online sites usually make you pay the full amount on a credit card at the time you book, and you may face a cancellation fee or not be able to get a refund at all if you cancel at the last minute. You should read the policies on the help or "about us" link on the page before deciding to book.

Book early: Discounts tend to dry up close to the booking date, particularly if a hotel is in a city that has a major event scheduled. If you can, make a booking as soon as you’ve decided on your travel dates.

Shop around: Not every online travel site has access to the same rates. This is particularly true with car rentals and airfares, which can change by the day. High-volume sites such as Orbitz or Expedia tend to have good deals on mass-market hotels. Specialty sites or sites run by cities or government tourist boards may have specials on smaller or more out-of-the way hotels in the part of the world you want to visit. There are also regional specialty sites for bed-and-breakfast places and hostels that are not on the big booking sites. Also, check to see if the hotel you are interested in has a direct booking site. That could save you the middleman fees.

Don’t show your hand: Hotels and car rental companies give discounted rates to websites in order to sell inventory that would otherwise sit idle and bring in no revenue. But as I found out on a recent car rental in Miami, finding a rate from Orbitz that was better than the rate I could get directly from the car rental company’s website meant I was considered a second-tier customer. After being given an upgrade to a better car, I handed the clerk my online booking voucher and I was told that if they had known when I arrived that I had that rate, they would have put me in a plain Jane car.

The same is true of hotels. Those paying minimal rates may be steered to the noisy rooms near the ice machine or the elevators, so don’t make a point of your rate until after you’ve been assigned a room.

Be flexible: After choosing your preferred departure date, check the price on some alternative dates. Moving your travel dates may save you significantly by avoiding holidays or special events, which are times when there is peak demand and no need for suppliers to provide discounts. Good times to bargain-hunt include the slow period from September to early December, in January after the holiday rush, or in April to early June.

Check before you click: The internet can be a powerful tool for researching travel. But when you’re ready to buy, the internet can’t replace the expertise of a trusted travel counsellor. Remember that the consumer protections offered by such groups as the Travel Industry Council of Ontario or the Travel Assurance Fund in British Columbia only cover travel booked through member agencies.

Also check whether a site will offer you extras, such as travel points or best-rate guarantees. For instance, the InterContinental Hotels Group, which includes Crowne Plaza and Holiday Inn, guarantees that its website rates are "the lowest rates publicly available on the internet" or it will match a lower rate, plus give you a 10 per cent discount on the lower rate.

But even here, it pays to read the fine print, because to take advantage of this guarantee, the lower-priced room you find has to be one of exactly the same type. And it doesn't apply to sites that let you bid on rooms without telling you the name of the hotel. Many chains also won't give you points in their loyalty programs if you book rooms through a site other than their own.

Hryniuk says he’s learned his lesson. He’d rather get the airline points than the savings he could potentially get from an online discount site.

"Next time I will just pay the extra $100 or $200 and buy a ticket that comes with points directly from Air Canada," he says.