[LS part of the answer is wrong, mine can be adjusted! (If you can't dial, it may just be that individual phones really can't dial or you can't));
As for writing information, it is also true:
If some mobile phones choose Pinyin when sending messages under traditional settings, they can input simplified Chinese characters-for example, most versions of Nokia;
Some can also be dialed in the information input. Each brand is different but generally acceptable. If you don't believe me, you can consult the place where you sell mobile phones.
Finally, whether the mobile phone is licensed or not depends mainly on the whole mobile phone, such as the label on the box: it is best to suggest that you buy it in a trustworthy place like PCCW, which is more secure.
Of course, if the mobile phone you bought in Hong Kong can't be simplified, I suggest you return it.
Of course, if you only like traditional English, it's ok, mainly because of your personal preference.