Hong Kong phone number format: +852, mobile prefixes, validation and messaging rules

A Hong Kong phone number is the country code +852 followed by eight digits, with no area code and no trunk prefix: a mobile looks like +852 5XXX XXXX from abroad and 5XXX XXXX at home. Mobile numbers start with 4, 5, 6, 7, 8 or 9 and landlines with 2 or 3, but only some blocks under each digit are mobile, and because porting has been possible since 1999, the prefix doesn't tell you the current network.

This guide is part of our phone numbers by country series. The tables are generated from libphonenumber's metadata, our MNP atlas and our public catalog. Example numbers are masked with X. We read the Office of the Communications Authority (OFCA) allocation dataset, updated 4 September 2026, and the government and Legislative Council documents cited below on 2026-10-10. This is a summary, not legal advice.

#What does a Hong Kong phone number look like?

Every ordinary Hong Kong number has eight digits, and you dial all eight anywhere in the territory. There are no area codes and no trunk 0, so the national number and the digits after +852 are the same. According to Wikipedia's summary, landlines moved to eight digits on 1 January 1995, when a 2 was put in front of the old seven-digit numbers.

People write the same number as 5XXX XXXX, 5XXX-XXXX, +852 5XXX XXXX or 852 5XXX XXXX without the plus. A numbering-plan library handles all of these if you pass the default region HK. The last form is unambiguous because OFCA reserves the national block 852 itself, so no local number starts with those digits. Store only the E.164 result, +8525XXXXXXX.

#Which prefixes are mobile numbers?

Hong Kong has never had separate mobile codes. Mobiles first started with 9, blocks under 5 and 6 followed, and when those ran short OFCA opened vacant blocks under 4, 7 and 8. Its press release of 5 February 2018 says the first 4, 7 and 8 mobile numbers were expected to be available for assignment that month: about 10.6 million new numbers, used alongside the existing 5, 6 and 9 mobiles and expected to meet demand until at least 2029 (OFCA, 2018). The same release scheduled a third phase from 1 July 2021, freeing 71 to 73 blocks after paging numbers moved out.

The table counts, for each 2-digit block, how many 8-digit numbers libphonenumber's mobile pattern for HK accepts:

#What else lives under the same first digits?

OFCA's allocation dataset (OFCA numbering plan) shows why a first-digit rule fails. Next to the mobile blocks it lists:

• 2 and 3: fixed services. Some 3 blocks are access codes rather than subscriber numbers.
• 58: fixed services in OFCA's "Class Two" category, not mobiles.
• 7: paging blocks such as 710, 711 and 716, next to the mobile blocks 70 and 71.
• 81 to 83: the personal number service, mixed with spare mobile blocks.
• 800, 801, 808, 809: freephone numbers with nine digits.
• 4500: machine-to-machine numbers with twelve digits, assigned to the mobile operators.
• 1: short codes, including the emergency numbers 999 and, from mobiles, 112.

Many mobile blocks are marked spare in the dataset: all of 43, 45, 48, 49, 72, 73, 85 to 87 and 89, for example. A number there has the right shape but nobody can hold it today. libphonenumber follows the assignments, so it rejects them.

#Why a prefix doesn't name the operator

OFCA allocates each block to one operator. Most mobile blocks belong to Hong Kong Telecommunications (HKT), China Mobile Hong Kong, Hutchison Telephone (which trades as 3) and SmarTone, with smaller holders such as China Unicom (Hong Kong) and China Telecom Global. That tells you who first held the range, not who serves the number after a port, so we don't print a prefix-to-operator table.

#How do I validate a Hong Kong number in code?

Use a libphonenumber port with full metadata and the default region HK. There is one Hong Kong trap. OFCA assigns 008 as an international access code (one operator's gateway), and libphonenumber's international-prefix pattern for Hong Kong accepts 00 plus an optional digit such as 1 or 8. So 00852 5XXX XXXX, a common way to write a Hong Kong number for dialling from abroad, is read as 008 plus 52, Mexico's country code, and fails. The function below turns a leading 00852 into +852 first; in Python's phonenumbers, apply the same rewrite before phonenumbers.parse(text, "HK").

JavaScript (npm install libphonenumber-js):

import { parsePhoneNumberFromString } from "libphonenumber-js/max";

/** "5XXX XXXX", "+852 5XXX XXXX", "00852 …", "852…" → E.164 for a Hong Kong mobile, or null. */
export function normalizeHk(raw) {
  const input = String(raw).trim().replace(/^00(?=\s*852)/, "+"); // 00852 would parse as 008 + 52 (Mexico)
  const phone = parsePhoneNumberFromString(input, "HK");
  if (!phone?.isValid() || phone.country !== "HK" || phone.getType() !== "MOBILE") return null;
  return phone.number;
}

We ran it on 2026-10-10 with libphonenumber-js 1.13.13 (metadata 9.0.39), and the same logic in Python with phonenumbers 9.0.40, which reads 00852 the same way. Both returned one E.164 number for the national, +852, 00852, 852 and bracketed forms, and nothing for a seven-digit number, a number in the unused 41 block, a landline, a personal number or a Macau number. The table shows the raw library calls without the 00852 fix. The shape regex column tests ^(?:\+852|00852)?[4-9]\d{7}$, a typical "8 digits starting 4 to 9" rule, after spaces, dashes and brackets are removed:

Rows 8 and 10 are why the regex isn't enough: a number in the unused 41 block and a personal number both pass it. Row 3 is the 008 trap described above. Our JavaScript validation guide and why an E.164 regex is not enough cover the general case.

#Hong Kong, Macau and mainland China are separate plans

The ITU assigns three different country codes (ITU E.164 list): +852 for Hong Kong, +853 for Macau and +86 for mainland China. A call between them is an international call. Macau numbers also have eight digits, with mobiles starting 6, so a bare 6XXX XXXX could belong to either city: ask for the country on forms instead of guessing. A mainland mobile has 11 digits starting with 1 and doesn't validate under HK at all. Our China phone number format guide covers +86 in detail.

#Does number portability change the carrier?

Yes. The Telecommunications Authority directed all fixed and mobile operators on 28 August 1998 to provide mobile number portability by 1 March 1999, and the service launched that day. In its first four weeks, 88,116 numbers were ported (LegCo paper, 1999). Today the technical rules are OFCA's HKCA 2103 and 2104 specifications, which describe a database solution with a central administration database. The Hong Kong row of our MNP atlas:

OFCA counted 50,987 successful ports in March 2026 alone, so prefix tables go stale quickly. If you route, price or score numbers by operator, look up the current network per number. Our MNP atlas compares Hong Kong with other countries.

#Which messaging apps and channels reach people?

SMS reaches every active mobile. We haven't found a published measurement of app use in Hong Kong that we can verify, so we don't quote shares. Check which apps your opted-in customers are registered on, route from that, and keep SMS as the fallback. The flow in the last section returns WhatsApp and Telegram registration in the same call as the line type, and our channel-by-country guide covers the method.

#What are the rules for SMS, sender IDs and OTP?

Summaries of the primary texts, checked on 2026-10-10. Not legal advice; ask counsel how they apply to you.

#Real-name SIM registration (Cap. 106AI)

The Telecommunications (Registration of SIM Cards) Regulation (Cap. 106AI) came into force in September 2021. New SIM service plans and pre-paid cards had to be registered before activation from 1 March 2022, and existing pre-paid cards by 23 February 2023. Since 24 February 2023, every SIM card issued and used locally must complete real-name registration before activation or continued service (Hong Kong Government, 2023). For a sender, that means a working Hong Kong mobile belongs to a registered SIM. It doesn't mean you can see who registered it.

#The "#" sender prefix (SMS Sender Registration Scheme)

From 28 December 2023, OFCA's SMS Sender Registration Scheme lets registered organisations send with sender IDs that start with #. Networks block other messages whose sender ID contains #, and recipients don't need to do anything (OFCA, 2023). The scheme started with telecom operators and was opened to all sectors on 21 February 2024. It doesn't cover messages where the recipient is expected to reply by phone. If you send OTPs or alerts to Hong Kong, ask your provider whether your sender ID can join.

#Commercial messages (Cap. 593)

The Unsolicited Electronic Messages Ordinance (Cap. 593) governs commercial electronic messages, including SMS. Messages with a Hong Kong link must include accurate sender information and an unsubscribe facility (sections 8 and 9), and OFCA runs do-not-call registers that people can add their numbers to (Cap. 593). A one-time passcode the user asked for isn't marketing, but keep it free of offers and don't reuse numbers collected for verification for marketing without consent.

#What changed recently?

The rows for HK and +852 in our numbering-plan changes dataset, built from libphonenumber's release notes:

Latest numbering-plan updates for HK: 2026-09-09 (v9.0.39), 2026-08-26 (v9.0.38), 2026-02-25 (v9.0.25), 2026-01-13 (v9.0.22), 2025-12-17 (v9.0.21).

In our numbering-plan research, Hong Kong was among the three regions whose metadata changed most often between 2019 and September 2026. Each new block OFCA assigns from its spare ranges needs a metadata update before libraries accept it. Update your validation library at least monthly, or new subscribers in fresh blocks will fail your forms.

#What can MobileValidate check for Hong Kong numbers?

Generated from our public catalog:

* bulk jobs only. Catalog as fetched on 2026-10-10; the live list is at GET /v1/services.

Here is a practical flow: normalise with normalizeHk() from above, then one lookup returns the line type, the current network and WhatsApp and Telegram registration for a batch of numbers. It uses the public sandbox key mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym and our test values, which are UK drama numbers. The sandbox accepts only those, so the run below uses them; with a live key, pass the output of normalizeHk(). We ran it on 2026-10-10 with Node.js 24.

const API = "https://api.mobilevalidate.com/v1/lookup";
const KEY = process.env.MOBILEVALIDATE_API_KEY;

/** One lookup for a batch of E.164 numbers: line type, current network and two messaging-app checks. */
export async function profile(numbers) {
  const res = await fetch(API, {
    method: "POST",
    headers: { Authorization: `Bearer ${KEY}`, "Content-Type": "application/json" },
    body: JSON.stringify({ numbers, checks: ["carrier", "whatsapp", "telegram"], wait: 5 }),
  });
  if (!res.ok) throw new Error(`lookup failed: ${res.status}`);
  const { results } = await res.json();
  return results.map((r) => {
    const c = r.checks;
    const carrier = c["network.carrier"].status === "completed" ? c["network.carrier"].attributes : null;
    const app = (code) => (c[code].status === "completed" ? c[code].registered : null); // null = unknown, never false
    return {
      number: r.e164,
      lineType: carrier?.line_type ?? null,
      network: carrier?.carrier ?? null,
      whatsapp: app("whatsapp.registered"),
      telegram: app("telegram.registered"),
    };
  });
}

console.table(await profile(["+447700900001", "+447700900002", "+447700900003", "+447700900005"]));

Keep null apart from false: null means we don't know, and it's never billed. For live porting status and reachability, add the MNP or HLR check. See carrier lookup and Telegram number check for the fields, and pricing for prices.

#What are the key takeaways?

• Hong Kong numbers are +852 plus 8 digits, with no area code and no trunk 0; store them as +852XXXXXXXX.
• Mobile blocks sit under 4 to 9, but 58, the 81–83 personal numbers, pagers in 7, 800 freephone and spare blocks are not mobiles: validate with a maintained library and the region HK.
• Rewrite 00852 to +852 before parsing, or libphonenumber reads it as 008 plus Mexico's 52.
• Porting has run since 1 March 1999, so a prefix shows the original operator, not the current one.
• Every SIM used locally has been real-name registered since 24 February 2023, and registered business senders use # sender IDs.
• Hong Kong (+852), Macau (+853) and mainland China (+86) are separate numbering plans.

Platform, regulator and company names are used descriptively. MobileValidate is not affiliated with any of them.