Telstra has begun notifying travellers among its 15.3 million mobile subscribers about changes to international roaming rates.

It trumpets as a victory for consumers changes that will mean identical call charges regardless of making or receiving calls overseas.

But a closer inspection of the new price schedule reveals that from March 24, globetrotters will be billed between 100 per cent and 500 per cent extra whenever they accept international calls in more than 180 countries worldwide.

Significantly, those countries include the most common destinations for Australian travellers, such as New Zealand (up from 64¢ to $1.50), Indonesia ($1.55 to $4) and Europe with Italy, Germany, France and Spain all attracting rises of at least 194 per cent. Accepting calls in the UK, meanwhile, will jump from 70¢ to $2, and in Ireland 77¢ to $2.50. The greatest increase relates to Portugal where an incoming international call leaps 426 per cent, from 76¢ to $4.

Only 13 countries see a reduction in incoming call fees. They include India, Afghanistan, Gibraltar and the the Federated States of Micronesia and Bhutan.

While some incoming roaming charges have gone up, Telstra claims the impact has been offset by reductions in outgoing call rates.

A Telstra spokesman said current usage patterns show 70 per cent of international calls are outbound and only 30 per cent are received, adding: "The revenue impact for Telstra from the change in rates is relatively neutral."

But the Australian Communications Consumer Action Network (ACCAN) lashed out at Telstra for introducing "massive price hikes" under the guise its global roaming rates had become more user friendly.

ACCAN spokesman Mark Callender said making a call within popular destination countries had also skyrocketed. "For example, if you're travelling in Bali, the cost of making a call to a local hotel has increased by 349 per cent."

The price hikes blindsided federal Communications Minister Malcolm Turnbull who just weeks ago released draft legislation specifically designed to address the global roaming rip-off – but the law, if passed, would only apply to calls in New Zealand.

The Communications Department was trying to make sense of the new Telstra charges over the weekend following inquiries by Fairfax Media on Friday.

Mr Turnbull has personal experience of the sting of unexpected roaming charges after he personally repaid $13,000 of a $26,000 roaming bill charged to the taxpayer after a 2011 trip to Hong Kong and Europe.

A spokesman for Mr Turnbull declined to respond to specific questions but said the Trans-Tasman initiative would make a difference.

Consumer groups and telco experts accused Telstra of "gouging" customers and the government of doing little to protect Australians against unjustified, dramatic price rises.

"The direct marketing material from Telstra explaining the changes to its customers is misleading at best," Mr Callender said. "They have not made clear that each country now has a single price for every type of call and that most call types are actually more expensive."

Mr Callender was referring to a letter distributed to customers earlier this month, in which Telstra dedicated a single line to the change.

Optus and Vodafone have already introduced a flat pricing structure for outgoing and incoming calls but Telstra has set its fees much higher in most cases. Optus charges $1 a minute for receiving calls in the US while Telstra will charge $3.

Tony Simmons, the founder of Full Circle, a company that advises corporates on how to reduce telco bills, accused Telstra of "gouging" to protect its profit margins on roaming.

"They are bringing pricing up to the highest common denominator rather than the lowest to protect their margins at the expense of customers," he said.

The Telstra spokesman denied the letter was misleading. "We were changing 792 prices – which is not possible to communicate in a single letter, hence why we directed people to the website for more information." He said the "simplification" of call rates was designed to help customers "more easily calculate" the costs of making and receiving calls while overseas.

Twitter: @eamonnduff