Telstra's new international roaming day pass looks good on paper but overseas travellers need to read the fine print.

Telstra has always been more expensive than its rivals, which it justifies with its wider Australian coverage, but unfortunately the telco also expects its customers to pay through the nose when travelling. Telstra has finally revamped its international travel passes, but you won't always get a better deal.

Until now Telstra has offered 3, 7, 14 and 30-day passes, with the ability to specify what time of day your pass began. This meant a 3-day pass could get you through from dinnertime Monday to dinnertime Thursday, although you sometimes had to argue with Telstra's global roaming hotline which wanted to count that as four days – thus pushing you onto a 7-day pass.

Now that ambiguity has been removed with a flat $10 per-day deal for customers on post-paid plans. Sometimes this new deal will work against you, other times it will work in your favour.

The new travel day passes expire at midnight regardless of what time you started using them. So if you arrive at your destination at dinnertime your first day pass will only last a few hours, not until dinnertime the next day.

This means that roaming from dinnertime Monday to dinnertime Thursday will definitely be counted as four days, costing you $40 rather than $30 when travelling to a Zone 2 country like South Korea. The old multi-day passes are no longer available, something I had to double-check with Telstra after once again getting conflicting answers from the telco's support people.

Telstra's international roaming now works on calendar days, not blocks of 24 hours. Of course if you need to use global roaming from dinnertime Monday until dinnertime Friday you'll now only pay $50 for five days, instead of stepping up to the old $70 7-day pass.

On the off chance that you manage to go a whole day without using your phone while travelling you won't be charged for that day, although that's very unlikely with a smartphone which tends to use mobile data in the background unless you're on WiFi all day.

You're still entitled to unlimited calls and texts on the new travel deal, but Telstra has changed the way it handles mobile data while you're overseas. Once again, it's not always a better deal.

Previously a three-day pass entitled you to 225MB of data spread across the three days, with the longer passes offering more. Now you receive a flat 100MB per day allowance, which seems more generous, but unfortunately that data doesn't roll over.

On the old travel passes you could use the bulk of your data in one day if need be, but now you'll start paying the 3 cents per MB excess data fee as soon as you go over 100MB in a single day. Alternatively you can pay $25 for another 1GB of data which rolls over for 31 days and is only used if you go over your 100MB daily allowance.

Either way it's still better than paying Telstra's horrendous $3 per MB Pay As You Go rate if you don't have a travel pass.

The death of rollover international data, unless you pay for that extra data pack, is likely to make some Telstra users very unhappy – perhaps finally encouraging them to look for an alternative when they travel. What's your global roaming strategy and will Telstra's new deals win you over?