Having a mobile phone account in New Zealand has become quite a bit less of a hassle than it was just a few years ago. Young people talk on mobiles instead of texting only or chatting over landlines and it's possible now to fire up smartphone data connections without one eye on the usage meter - and with 4G everywhere, it's really quick data too. With that in mind, it seems a shame that SIM locking has reared its ugly head again. This is a feature in GSM networks that allows providers to restrict or lock phones bought from them so that only their SIM cards can be used in them. The idea here is that telcos will "subsidise" phones - or on some plans, include it for no money upfront - but you have to stay on their networks. Having to pay less upfront for phones is an attractive proposition for many, especially when it comes to expensive smartphones. However, telcos are not charities and they make up for the cost of the device in usage charges over the time it is locked to their networks. You're not going to save money in other words, and likely lose out over time as better deals and plans come online. SIM locking is common overseas and it's now starting to creep back into New Zealand, after causing an uproar in 2008. At that time, Vodafone, the dominant telco, threatened it would lock all its devices as Telecom launched its XT GSM network and 2degrees got going, but backed down in the end as the Commerce Commission expressed concern. 2degrees has been a vocal opponent of SIM locking, but now they say they'll have to start doing it too, to remain competitive with lower upfront handset prices ahead of the Christmas and back-to-school seasons. Mathew Bolland, 2degrees' director of corporate affairs, agreed that SIM locking is a retrograde move in 2014 and that it wouldn't be a popular move. Bolland said the telco has no option as Spark/Skinny and Vodafone are now both locking devices to a much greater degree than before. The SIM lock isn't permanent - 2degrees customers can stump up $30 to unlock their phones, or wait nine months, and then shift to Spark or Vodafone. You'd think that the Commerce Commission would frown upon telcos again trying to lock in customers with SIM locking to prevent "churn", or moving to other providers with more competitive deals, but no. The regulator has done a one-eighty on SIM locking lately. "We don't believe SIM locking is anti-competitive. It's analogous to early termination provisions in post-pay contracts," a commission spokesperson told me. "Customers have choices of buying handsets directly or honour some sort of undertaking if they accept a handset subsidy," the spokesperson added. Those arguments are both flimsy though. First, a contract between a telco and a person or company doesn't stop customers from moving to other providers. Sure, you'll have to honour the contract or pay termination fees (which can be exorbitant), but you can use your phone on another network if it's compatible with it. Let's say Telco A's service in your area is bad but Telco B is good; you need phone service and will bite the bullet and switch providers. With an unlocked phone, you can. Large multinational telcos can use their market power to hammer out exclusive deals with phone makers and offer handsets to customers at low initial cost, provided they agree to be locked in over a period of time. They can also offer network features and services exclusively to locked-in customers - and refuse to connect customers who have bought handsets directly. Telcos may also be tempted to offer plans with more expensive local and roaming rates to customers who bring their own handsets so as to steer them towards locked ones with better deals for calling, texting and data. What's more, locking cheaper handsets to prepaid SIMs targets lower-income earners and students who need a device but might struggle to buy one outright. None of the above should come as news to the commission, which has had plenty of time to learn from telco shenanigans here and in overseas markets. SIM locking is a tool for telcos to reduce competition, in other words. It's wildly unpopular with customers overseas, and some countries have banned either the practice or the sale of locked devices. When the United States recognises that SIM locking is anticompetitive, and this year enacted a law "to promote consumer choice and wireless competition by permitting consumers to unlock mobile wireless devices, and for other purposes", it's surprising our telco regulator should hold the opposite view.