Before you start

A valid passport (must be the same passport for life of the account; renewing it later means updating the bank).
Ideally a long-stay non-immigrant visa or extension stamp (DTV, ED, retirement, Non-B, marriage). Tourists are frequently refused.
Proof of a Chiang Mai address: a Certificate of Residence from Chiang Mai Immigration, OR a work permit, OR (some branches) a signed rental/condo lease + TM30 receipt.
A Thai mobile number (needed for SMS OTP, the bank app, and to link PromptPay).

Step-by-step

1
Get proof of address before the bank visit
Most Chiang Mai branches now ask for a Certificate of Residence (issued by the Chiang Mai Immigration Office near the airport — the former Promenada office relocated — ~300-500 THB, 1-3 days, or same-day via an agent) or a work permit. If you have neither, a few branches accept a lease plus your TM30 (address-registration) receipt — call ahead and ask the specific branch. Bring your Thai SIM so they can register the app on the spot.
In personWho: You (Immigration issues the residence certificate)Same day to 3 days for the certificate~300-500 THB official; ~1,000-2,000 THB via agent
2
Pick a foreigner-friendly bank and branch
Bangkok Bank is the most consistently willing to open accounts for foreigners and has English-capable staff at branches near Nimmanhaemin and the malls (Maya, Central Festival). KBank has the best app and English support but is stricter on visa type. SCB and Krungsri also work. Branches inside or near big malls deal with foreigners daily and say yes more often than small suburban branches. Go on a weekday morning with all documents.
In personWho: You30-60 min in-branch if accepted500-1,000 THB opening deposit
3
Open the savings account and take the debit card
You sign for a passbook savings account, make the minimum deposit, and pay the debit-card fee. US citizens must complete a FATCA / W-9 form (the branch will have it). You walk out with a passbook and usually an instant debit card. If a branch refuses outright, a Chiang Mai visa agent will open an account for you for roughly 1,500-3,000 THB — common and not frowned upon locally.
In personWho: You (or a visa agent acting with you)Same day~200-300 THB/yr debit card; agent ~1,500-3,000 THB if used
4
Activate the app and register PromptPay
Install the bank app (Bualuang for Bangkok Bank, K PLUS for KBank, SCB EASY, KMA for Krungsri), verify with the SMS OTP to your Thai number, then register PromptPay by linking your account to your passport-based ID and phone number in-app or at the counter. PromptPay turns your phone number into a QR you scan to pay almost anywhere — markets, songthaews, restaurants — usually free for small transfers. This is how daily payments work in Chiang Mai; few places want cash.
Mobile appWho: You15-30 min; PromptPay live within minutes to 1 dayFree (transfers under ~5,000 THB are free)

Documents you’ll need

Passport (with the visa/extension stamp)
Proof of long-stay status: Non-Immigrant visa or extension stamp (DTV/ED/retirement/Non-B/marriage)
Certificate of Residence from Chiang Mai Immigration, OR work permit, OR lease + TM30 receipt
Thai mobile phone number (for OTP and PromptPay)
Opening deposit in cash (500-1,000 THB)
US citizens: completed FATCA / W-9 self-certification

Things most newcomers don’t know

Bank choice and branch choice matter more than your paperwork — Bangkok Bank, and any branch inside a major Chiang Mai mall, say yes far more often than small branches.

Foreigners get refused at one branch and accepted at another the same day with identical documents; picking the right counter saves a wasted week of trying.

Source: Bangkok Bank foreign-customer guidance

QR payments are everywhere (night markets, songthaews, cafés) and small transfers are free; without PromptPay you fall back to cash and miss the whole local payment rail.

Source: Bank of Thailand PromptPay

If branches keep refusing, a local visa agent will open the account for ~1,500-3,000 THB — a normal, accepted Chiang Mai workaround, not a scam.

Newcomers waste days branch-hopping; the agent route is fast, legal, and widely used, especially for those on DTV or between visa types.

Source: community-reported (Chiang Mai expat practice)

Common mistakes to avoid

Assuming a tourist stamp is enough — many branches now refuse anyone without a long-stay visa or proof of address; don't show up empty-handed
Going to a tiny suburban branch where staff have never onboarded a foreigner — they default to 'no'. Use a mall or Nimman-area branch
Skipping the Thai SIM — without a local number you can't get the OTP, activate the app, or link PromptPay, and the account is half-useless
US citizens forgetting FATCA — without the W-9 self-certification the branch can decline or freeze the account later
Letting the account sit dormant — Thai banks can freeze inactive accounts and charge fees; run an occasional small transaction

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.