Playing by the same rules just won’t fly.

Buying international plane tickets for a steal has a different set of rules than for domestic tickets, says Jeff Klee, the CEO of CheapAir.com, which released data from more than 350 million international flights today. That includes different rules for when to buy and when to travel, he says.

And experts say there’s even more to it than that, so Moneyish pulled together these insider tips for scoring deals on international airfare:

Buy your tickets this far in advance
In general, to get the best deal, you should buy international plane tickets even further in advance than you would domestic tickets (which tend to hit their sweet spot, price-wise, between the 3 week to 3 1/2 -month ahead mark), says Klee. How far in advance depends on the country, CheapAir’s analysis found. This checklist lists the average number of days ahead you should book (remember, these are just averages so this won’t be true every single time) to get the best deal.
Canada: 59 days
Mexico: 61 days
Central America: 61 days
Caribbean: 76 days
South America: 81 days
South Pacific: 89 days
Asia: 90 days
Europe: 99 days
Africa: 119 days
Middle East: 119 days

Travel during these times of year
Even more so than with many domestic destinations, seasonality matters for deal-hunters when you’re going overseas, says Klee. Take Europe for example: It’s typically cheapest to travel there in winter, most expensive in summer, says Klee. For beach vacations in Mexico and the Caribbean, the most expensive time to travel is generally December to April and prices start to go down in May and June with the best prices in August and September. The Hopper apps is a simple way to figure out when is the cheapest time to fly somewhere.

Read the fine print
While you may be able to get away with just a small bag and no snacks on a domestic flight, it’s often harder to do that when you’re traveling overseas on a longer flight. That means you have to really watch the fees, particularly on low-cost airlines like WOW and Norwegian, says George Hobica, the founder of AirfareWatchdog.com. “I’ve seen super low fares on WOW that looked great in comparison to the bigger European and U.S. airlines, but when you factor in ancillary costs the European and US carriers are actually cheaper,” he says. “So don’t be suckered in by a low advertised fare before you look at the extras such as seat selection, bags, meals.”

Do not wait until the last-minute
Klee says CheapAir’s “biggest takeaway” from their analysis was that it is much harder to get a last-minute deal on an international flight than a domestic one. Of course, that doesn’t mean these don’t happen, just that they are unlikely. But if you’ve got the time to travel on a whim, sign up for a service like AirfareWatchdog, which tweets ultra-low last-minute fares, as well as other good airfare deals.

Fly on the right days
There’s at least one rule that’s true domestically and internationally: “Flying during the week is almost always going to give you better prices than will flying on the weekend,” says Klee. Take Europe, for example: Patrick Surry, the chief data scientist at Hopper.com says “you can save over $150” by being smart about when you fly. “Across the board, the best fares to Europe are found flying on Mondays, Tuesdays and Wednesdays and the highest fares flying on Sundays,” says Klee.