New Zealand's three mobile network operators have missed out on around $120 million in high-margin roaming revenue over the past 12 months, according to an Ecosystem estimate.
Today, the tide starts to turn with quarantine-free travel to-and-from Australia - the most lucrative market for outbound and inbound roaming.
And all three mobile players are looking to grab as big a slice of it as possible with new deals and features.
Vodafone NZ says the first day of the transtasman bubble coincides with the telco offering 5G roaming to a series of new international destinations to reach a current tally of 10, in preparation - and hope - for a further expansion of international travel.
"International 5G roaming is now available for $7 per day, per device, for travellers going to Australia," Vodafone chief technology officer Tony Baird says.
For when border restrictions ease Vodafone NZ also has a 5G option for those travelling to Germany, Italy, the Netherlands, Latvia, Luxembourg, Finland, China and Taiwan - with travel sim deals ranging from $29 to $99. Like rivals' travel sim deals, plans include a set number of minutes for "free" calls back to Australia.
Baird adds, "International travel is hopefully going to open up further soon, so we're continuing to work on deals with overseas network providers."
For travellers coming into New Zealand, Vodafone NZ's 5G network is now open to people roaming from Australia, China, Germany, Italy, the Netherlands, Saudi Arabia, Spain and Taiwan.
Vodafone NZ has also marked the opening of the transtasman bubble by changing its network banner to a "VF Kia Ora" message.
IPO candidate 2degrees has marketed the bubble opening with free-roaming to Australia for its business customers - with no extra charges to New Zealand customers who text, call or use data while across the ditch.
The three mobile operators have traditionally offered free transtasman roaming for consumers only.
2degrees says it's partnered with the three largest mobile operators in Australia for comprehensive coverage - although 5G is not an option.
For inbound travellers who want to pre-pay roam with 2degrees, the carrier has one-month deals ranging from $10 to $85.
A spokeswoman for Spark said: "We know Spark Business customers who travel across the Tasman will need the tools to keep working flexibly and remotely – so Spark's offer of 12-months of Microsoft 365 Business Basic for free with an Endless Mobile for business plan will deliver this for them.
"So we will be keeping Spark's roaming offer in market. This gives our business customers simplicity and great value with a seven-day bundle of texts, calling minutes and data for $20."
Spark offers travel sim plans from $29 to $59 for Australians arriving into NZ.
Spark's budget sub-brand Skinny offers incoming Australians travel plans from $28 to $88.
Kogan Mobile NZ (which resells access to Vodafone NZ's network) also has some keenly-priced deals for Aussies wanting to grab a local sim card. Its monthly prepay plans range from $15 to $35. They include calls back to Australia but are 4G only for data.