Purchase phone number
Payment-first: you do not pick a specific number, the system provisions one and
auto-assigns it. With usage-based billing active and a payment method on file, the
number provisions inline and bills per month on your usage-based invoice (there is
no checkout redirect). No payment method on file returns 402 PAYMENT_REQUIRED;
a regulated country returns 202 with status: "kyc_required" and a kycUrl.
Requires usage-based billing (the Usage plan). The maximum number of phone numbers is determined by the user's plan.
API key authentication - use your Zernio API key as a Bearer token
In: header
Preferred profile for the number. One number = one profile, so when the requested profile already holds a number the API assigns the next free profile instead (or creates one) and returns the actual assignment in profileId on the response.
ISO 3166-1 alpha-2 country for the number (default US). International numbers require usage-based billing. Tier 3/4 countries return 202 { status: "kyc_required", kycUrl } — the customer must complete KYC at that URL before the number is ordered. See GET /v1/phone-numbers/countries.
"US"Which of the country's offered number types to order (see types[] on GET /v1/phone-numbers/countries). Omitted = the country's default type, which is always the WhatsApp-safe choice. Capabilities, price, and KYC requirements are per (country, type): toll_free can never connect WhatsApp (400 when combined with connectWhatsapp:true), and wantsSms:true requires an SMS-capable type.
"local" | "mobile" | "national" | "toll_free"Area code (national destination code, e.g. 11 for Sao Paulo) the number must be in. Hard constraint: when the area has no deliverable inventory the purchase fails with 409 code AREA_CODE_UNAVAILABLE instead of assigning a number from another area, and later replacements stay in this area too. Omit for any area. Get live options from GET /v1/phone-numbers/availability (areaOptions).
^\d{1,4}$A phone number is the unit; WhatsApp is one optional feature. Pass false to buy a STANDALONE number (Calls/SMS only): provisioning skips the Meta pre-verify/OTP steps and the number activates immediately. Omitted defaults to the WhatsApp provisioning path. WhatsApp can be connected to a standalone number later from the connect flow.
trueSMS capability is per-number, not per-country. Pass true to provision from the SMS-capable inventory pool so the number can actually text (see also GET /v1/phone-numbers/available with sms=true, and smsAvailable on GET /v1/phone-numbers/countries).
falseDeclare WhatsApp intent on a STANDALONE purchase (connectWhatsapp:false). The number still activates and bills immediately, but if WhatsApp's buy-time check rejects the assigned number, it is automatically swapped for a WhatsApp-eligible one during the purchase instead of being delivered with WhatsApp unavailable. Ignored on the WhatsApp provisioning path (connectWhatsapp omitted or true), which always delivers a WhatsApp-verified number.
falseOptional idempotency key. Send the same value when retrying a purchase: if a number was already bought under this key, the API returns { status: "already_purchased", numberId, phoneNumber, profileId } instead of provisioning a second number. Generate a fresh key for each genuinely new purchase.
length <= 100Any second purchase within 10 minutes of a previous one is rejected with 409 code PURCHASE_VELOCITY as duplicate protection. Pass true to confirm the additional purchase is intentional (e.g. bulk provisioning).
falseResponse Body
application/json
application/json
application/json
application/json
import Zernio from '@zernio/node';const zernio = new Zernio({ apiKey: process.env.ZERNIO_API_KEY });const { data } = await zernio.phonenumbers.purchasePhoneNumber({ body: { profileId: 'profile_abc123', },});console.log(data);{
"message": "string",
"checkoutUrl": "http://example.com"
}{
"status": "kyc_required",
"country": "string",
"numberType": "string",
"kycUrl": "string"
}{
"error": "Unauthorized"
}{
"error": "string",
"code": "PURCHASE_VELOCITY"
}Check portability POST
Pre-flight portability check: whether each number can be ported in and whether it qualifies for FastPort, BEFORE the user commits to a port order (LOA, invoice, service address). Read-only; creates no order and bills nothing.
Release phone number DELETE
Release a purchased phone number. This will: 1. Disconnect any linked WhatsApp social account 2. Decrement the Stripe subscription quantity (or cancel if last number) 3. Release the number from Telnyx 4. Mark the number as released