ENC Mobile FAQ explained: taxes, refunds, renewals, number keeping and Wi-Fi Calling for the SIM shipped to China (2026)
The ENC Mobile FAQ has more than 100 answers, and most are written for people in the US who manage their own ENC account: self-service renewals in the account centre, a $3 number-keeping service, 90 days before a number is reclaimed, and refunds within 7 business days. If you are in China and bought LarkSIM's US T-Mobile physical SIM (ENC), a few rules differ: renewals are topped up by support, the number is cancelled after 30 days suspended, and as a special item it cannot be returned or exchanged once shipped. This guide sorts the official answers by topic and marks whether each one applies to this SIM. If you are still choosing, the case for it is simple: $28 (about ¥199) including the first month's 30 minutes and 100 texts; a real T-Mobile +1 number, not VoIP; shipped to China and tested before dispatch, receiving codes after 3 steps and about 5 minutes.
On this page
- 1. The short version: official rules vs this SIM
- 2. What are ENC-T and ENC-A, and which network does this SIM use?
- 3. Numbers and phones: choosing a number, porting, and which phones work
- 4. Taxes: the activation ZIP code decides
- 5. Activation and Wi-Fi Calling: the pitfalls the FAQ mentions
- 6. Why buy this SIM from LarkSIM
- 7. Renewals, number keeping and deactivation: the rule people misread most
- 8. Refunds: ENC allows 7 business days, this SIM cannot be returned once shipped
- 9. US–China dual number, DualData, roaming packs, hotspot: does this SIM need them?
- 10. Who to contact
- 11. Rules sorted: order when you are ready
- 12. FAQ
- 13. Related guides
The ENC help centre has five groups: ENC 101 (networks, porting, devices, buying, refunds, taxes), activation, ENC features (Wi-Fi Calling, the US–China dual number, number keeping, roaming, add-ons), account management, and SIM and phone settings. Below, in the same order, are the parts people in China ask about most; every answer can be checked in the ENC Mobile FAQ.
The official rules reflect the pages on 21 October 2026, and the SIM's rules follow the LarkSIM product page. Where the two differ, the product page and LarkSIM support apply to the SIM LarkSIM sells. Rules can change at any time, so check the pages on the day you act.
The short version: official rules vs this SIM
| Question | ENC official (direct account) | US T-Mobile physical SIM (ENC) |
|---|---|---|
| Network | ENC-T for speed, ENC-A for coverage; switching costs a fee | T-Mobile network; in China it runs on Wi-Fi Calling, not cellular |
| Number | Random number based on the activation ZIP code, no choosing; porting in is supported | Randomly assigned, may have been used before, cannot be chosen or changed |
| Phone | Must be unlocked and pass the compatibility check; no smartwatches or wearables | iPhone 6S or later, Chinese or overseas models; carrier-locked, jailbroken and SIM-adapter phones are not supported; Huawei does not work |
| Taxes | Based on the ZIP code entered at activation; later address changes do not affect it | Also set by the activation ZIP; renewals cost ¥66–99 a month, cheaper in tax-free or low-tax states |
| Renewal | Self-service or auto-renew in the account centre, or account balance | No self-service top-ups; LarkSIM support renews it: email support@larksim.com |
| How long before the number goes | Suspended first, permanently deactivated after 90 consecutive inactive days | Cancelled after 30 days suspended |
| Number keeping | $3 per 30 days, up to 120 days at a time | Not available; keep the number by renewing monthly |
| Refunds | New, unactivated physical SIMs returned within 7 business days | Special item: no returns or exchanges once shipped |
| Data | Included by plan, with data and roaming add-ons | No data; use it on Wi-Fi |
In short: what the FAQ says about numbers, taxes, Wi-Fi Calling and support mostly applies; for renewals, deactivation, number keeping and refunds, follow the US T-Mobile physical SIM (ENC) product page.
What are ENC-T and ENC-A, and which network does this SIM use?
According to the FAQ, ENC Mobile offers two networks: ENC-T is built for speed (cities, campuses, 5G, hotspot use) and ENC-A for coverage (suburbs, rural areas, long drives). You can switch between them, but it needs a new SIM or eSIM; the first switch per number is free and later ones may cost $10 (FAQ: network coverage).
The US T-Mobile physical SIM (ENC) LarkSIM sells is on the T-Mobile network, as its product page states. In China the SIM does not use cellular service at all: texts and calls go over Wi-Fi Calling, so the speed-versus-coverage choice hardly matters and there is no need to switch. If you later move to the US, check ENC's coverage map then.
Numbers and phones: choosing a number, porting, and which phones work
- check_circleChoosing a number: the FAQ says new numbers are generated at random from the ZIP code you enter, and number selection is not offered. This SIM is the same: the number is random, may have been used before, and cannot be changed.
- check_circlePorting in: ENC accepts US numbers ported from other carriers, using the old carrier's account number, transfer PIN and billing address; it usually takes 10 minutes to 2 hours. LarkSIM's SIM comes with a new number and its product page does not offer porting, so email support first if you want to bring a number.
- check_circlePhone requirements: ENC requires an unlocked phone that passes its compatibility check (dial *#06# for the IMEI); locked phones and wearables such as smartwatches are not supported. This SIM's product page is more specific: iPhone 6S or later, Chinese or overseas models; carrier-locked, jailbroken and SIM-adapter phones are not supported, Huawei phones do not work, and for other Android phones please email before ordering.
Taxes: the activation ZIP code decides
The FAQ says the taxes on your bill include federal, state, city and local taxes and surcharges, and the rate is based on the ZIP code entered when the number is activated. Changing your billing or mailing address later does not change it (FAQ: taxes).
This matters just as much for this SIM. The same monthly plan costs ¥66–99 to renew, and the difference is mostly state tax. The US ZIP code asked for at activation has nothing to do with your delivery address in China, so pick one in a tax-free or low-tax state; it cannot be fixed after activation.
Activation and Wi-Fi Calling: the pitfalls the FAQ mentions
- check_circleWhen the plan starts: the 30-day cycle starts on the day activation succeeds.
- check_circleEnabling Wi-Fi Calling: on a direct ENC account you first enable Wi-Fi Calling in the account centre with an E911 emergency address, then turn it on in the phone. If the E911 address is rejected, enter only the street address without the flat number; if it says the SIM is invalid, wait an hour and try again.
- check_circlePhone says "contact your carrier": for people outside the US, the FAQ suggests switching the phone's network environment back to the US before turning on Wi-Fi Calling. This is why the product page says first activation needs an overseas network environment.
- check_circlePicture messages do not arrive: the FAQ says Wi-Fi Calling and international roaming do not support MMS. Missing picture messages is expected; verification codes are normally plain text messages and are not affected.
LarkSIM's SIM follows the 3 steps on its product page: connect the iPhone to Wi-Fi in an overseas network environment, insert the SIM and turn on Settings → Phone → Wi-Fi Calling, then wait 3–5 minutes for Wi-Fi Calling to appear in the status bar. Screenshots are in the ENC Mobile activation guide; if there is no signal, see ENC SIM shows no signal.
Why buy this SIM from LarkSIM
If you are in China and want a US number that keeps receiving verification codes, these are the reasons to order:
- check_circleFirst month included: $28 (about ¥199) covers the first month's 30 minutes of US calls and 100 US texts, so the SIM can receive codes as soon as it is set up, with no extra plan to buy.
- check_circleA real carrier number: a +1 mobile number on T-Mobile, not a VoIP number or a shared number from an SMS-receiving site, so account recovery codes keep reaching you.
- check_circleShipped to China, tested first: no US trip needed, and every SIM is checked before it is sent.
- check_circleThree steps, about 5 minutes: join Wi-Fi, turn on Wi-Fi Calling, wait 3–5 minutes. If you get stuck, ENC has Chinese-language support and LarkSIM support answers by email.
- check_circleNo roaming pack for codes in China: the official roaming add-on for 50 minutes and 50 texts costs $5; this SIM receives texts over Wi-Fi Calling on Wi-Fi with no roaming charge.
- check_circleRenew with one email: no need to register or pay in an official account yourself. Email LarkSIM support before expiry and they top it up; the same plan costs ¥66–99 a month.
Order now: Buy the US T-Mobile physical SIM (ENC), $28 (about ¥199) including the first-month plan.
Renewals, number keeping and deactivation: the rule people misread most
ENC's direct rules: renew manually in the account centre or turn on auto-renew, paying by bank card, account balance, Alipay or WeChat Pay. If you do not renew, service is suspended, and after 90 consecutive days inactive the number is permanently deactivated (FAQ: plan status and renewal). ENC also has a number-keeping service that pauses the main plan for $3 per 30 days, keeps 30 minutes and 100 texts, and lasts up to 120 days at a time (FAQ: number keeping).
- check_circleHow to renew: before expiry, email support@larksim.com with the SIM's US number and support tops it up.
- check_circleCost: the same monthly plan, 30 minutes and 100 texts, at ¥66–99 a month depending on the tax in the number's state.
- check_circleWhen: renew before the plan expires instead of waiting for suspension. Once cancelled after 30 days the number cannot be recovered, and accounts tied to it stop getting codes.
Refunds: ENC allows 7 business days, this SIM cannot be returned once shipped
ENC's refund rules: a new physical SIM that is unused, undamaged and not activated can be returned to their address within 7 business days for a full refund, excluding shipping. Promotional SIMs, eSIMs, add-ons and services such as number keeping are non-refundable, and parcels shown as delivered but lost for customer-side reasons are not refunded (FAQ: refund policy).
The SIM LarkSIM sells is a special item and cannot be returned or exchanged once it has been shipped. You can ask to cancel an order before it is packed or shipped, and items that arrive faulty or wrong are handled under the refund policy. So check your phone first: iPhone 6S or later; carrier-locked, jailbroken and SIM-adapter phones are not supported. Every SIM is tested before shipping, so the one you receive has been checked.
US–China dual number, DualData, roaming packs, hotspot: does this SIM need them?
| Official feature | What the FAQ says | This SIM |
|---|---|---|
| US–China dual number | A random Chinese virtual number linked to the US number for receiving texts; first month free, then $1.99 a month plus tax, with ID verification | Not included; ask support first |
| DualData | Only on the ENC-T Unlimited Pro plan: 10GB usable in the US, mainland China, Hong Kong and Taiwan | Not applicable; this SIM has no data |
| International roaming add-ons | 1GB data $8; 50 minutes plus 50 texts $5; no auto-renew | Not needed; texts arrive over Wi-Fi Calling on Wi-Fi in China |
| Data add-ons and hotspot | 1GB $6, 2GB $10; hotspot allowance by plan | Not applicable; this SIM has no data |
| Refer a friend | $15 credit each after the friend activates an eligible plan | Not applicable |
This SIM has one clear job: a real US +1 number that, on Wi-Fi in China, sends and receives US texts, makes and takes US calls, and receives verification codes. Your own Wi-Fi provides the internet, so none of these add-ons are needed.
Who to contact
- check_circleActivation, signal, number status: ENC's official support, with Chinese-language service. China 400-990-6699, US +1 909-666-1188, dial 611 from the SIM, or email help@encmobile.com (the site says replies within 24 hours); on WeChat, search for the official account "迎客ENCMobile".
- check_circleOrders, shipping, renewals, after-sales: LarkSIM support at support@larksim.com, with your order number if you have one.
- check_circleForgot the voicemail PIN: the FAQ says to dial #793# from the phone, which resets it to the last four digits of the number.
Rules sorted: order when you are ready
Most rules in the ENC FAQ are written for people in the US using data plans. If you are in China and just need a US number that keeps receiving codes, the US T-Mobile physical SIM (ENC) is the simpler route: $28 (about ¥199) including the first month's 30 minutes and 100 texts, a real T-Mobile +1 number, shipped to China and tested before dispatch, 3 steps and about 5 minutes to set up, and renewals by emailing support.
Buy the US T-Mobile physical SIM (ENC); after ordering, track delivery on the order page, and email support if any step is unclear once it arrives.
FAQ
Do the rules in the ENC Mobile FAQ apply to the SIM LarkSIM sells?expand_more
How long until an unrenewed ENC number is reclaimed?expand_more
How are ENC taxes calculated, and does changing my address lower them?expand_more
Can I return an ENC SIM?expand_more
Can I choose an ENC number or port my existing US number?expand_more
Can I use ENC's number-keeping service on this SIM?expand_more
Can I receive picture messages over Wi-Fi Calling?expand_more
What is ENC Mobile's support number?expand_more
Real +1 number · T-Mobile network · Card checked before dispatch
US T-Mobile physical SIM (ENC)
A real US +1 mobile number, not VoIP, delivered as a physical SIM to your address in China. Check the current price, Wi-Fi Calling and keep-number notes on the product page before ordering.