Get your phone number first: SIM cards in Taiwan
It's as important as your ID number to get around
Guide 2. If you read the banking guide, you know the rule: SIM before bank. When readers with years of account-opening experience weighed in on that guide, the one thing everyone agreed on was the standard document set: passport, ARC, and a local number. This is the local number half. It is the easiest errand on your arrival list, if you do it in the right order.
In Taiwan, your phone number is not just a phone number. It is the key everything else hangs off. The bank wants it for SMS verification. So does the NHI app, food delivery, your landlord, and every LINE group you will ever be added to, which in this country means your entire social and professional life. Show up at other counters without a local number and you will find that half of them cannot finish processing you.
So run this errand first. Before the bank, before the apartment hunt. It takes twenty minutes.
The one answer
Chunghwa Telecom (中華電信). Prepaid SIM (預付卡) first. Buy it at the airport counter when you land, or at any Chunghwa store in town.
Why Chunghwa: biggest network, strongest coverage outside Taipei, and the most practice processing foreigners. Taiwan Mobile (台灣大哥大) and Far EasTone (遠傳電信) are perfectly good networks too, and if one of their stores is closer, you will not suffer. But if you want one answer, it is Chunghwa.
For myself, I use Taiwan Mobile as most of friends and family are using it and it saves money on the in-network calls. In most cases, city or national call charges can be quite significant based on my experience. Also, their customer service is marvelous and pleasant. Despite the language barrier, their representative has made their best attempt to explain things in detail.
Why prepaid first: monthly contracts (月租) need an ARC, typically run two years, and charge real money to break. On day one you may not have an ARC yet, and you definitely do not know your data habits or how long you are staying. Prepaid gets you a working number with zero commitment. Convert to a monthly plan later if you want. The number can come with you.
The documents: what the rule says, and what the counter does
Taiwan officially requires two identity documents to register any SIM, including prepaid. Chunghwa’s published rule: a primary ID (passport original, entry permit, or ARC) plus a secondary one (ARC, NHI card, driver’s license, another passport, or a student ID).
In practice, recent arrivals report that airport counters often process tourists with just a passport, and enforcement of the second document varies by counter and by day. Sound familiar? It is the same pattern as the banks: the written rule is stricter than the average counter, and the strictness you meet depends on who is behind it.
The move is the same as the banking guide, and it costs nothing: bring a second document anyway. Your entry stamp plus a home driver’s license covers you at the airport. In town, once you have an ARC, passport plus ARC settles it. A signature on the form is fine here, no chop needed.
Where and what to buy
At the airport: telecom counters sit right after customs at Taoyuan and are open long hours. Prepaid tourist packages come in day blocks (5, 10, 15, 30 days) with unlimited data and some call credit. The clerk installs it and tests it before you walk away. eSIM is available if your phone supports it.
In town: any Chunghwa direct store. Search 中華電信 in Google Maps; there is one near you. Staying months rather than weeks? Say so, and ask for standard prepaid instead of a short tourist package. Top up at any convenience store or in the app.
What not to buy on week one: a two-year contract. The discounted-phone offer is tempting. But the math rarely favors someone who does not yet know their address, their data habits, or their timeline, and the fine print outlives many ARCs.
The catches
Your number becomes infrastructure. Choose once. Every account you open in Taiwan ties to this number, starting with your bank. Changing numbers later means re-verifying yourself everywhere you have ever registered. So do not treat the first SIM as disposable. Get a number you intend to keep. If you move to a monthly plan later, convert or port the number rather than starting over.
Keep prepaid alive. Prepaid credit comes with a validity window, and a long-idle SIM can be deactivated. Leaving Taiwan for a stretch? Top up before you fly. There are also reports of long-term prepaid users being asked to redo identity verification years later; if your data suddenly dies, a store visit with passport and ARC usually revives it.
Contracts: bring both documents. When you do sign a monthly plan, take passport and ARC. Foreigners commonly report being asked for both where locals show one card. Annoying, normal. Some stores also reportedly match contract length to your ARC validity, so a freshly renewed ARC makes for an easier signup than one expiring soon.
Unlocked phone required. A phone locked to your home carrier will not take a Taiwanese SIM. Sort that out before you fly, not at the counter.
The short version
Land. Walk to the Chunghwa counter. Passport plus one more document, just in case. Buy prepaid. Guard the number like a second passport, because functionally it is one. Then go open your bank account.
Guide 1 covers that bank visit, updated with corrections from readers who have opened more accounts here than I have. If your SIM story went differently, reply to this email. Reader corrections have already made these guides better, and they decide what I write next.