> ## Documentation Index > Fetch the complete documentation index at: https://docs.polymorfa.com/llms.txt > Use this file to discover all available pages before exploring further. # Calling best practices > Keep a linked-device Number in good standing when it places WhatsApp calls: start gradually, call people who expect your call, and move business-initiated calling at volume to a Cloud API Number. A Number connected as a linked device places calls as the WhatsApp or WhatsApp Business app on the phone. WhatsApp applies its terms and policies to those calls as it does to calls from any phone. It restricts or bans numbers whose calling looks like spam or draws reports, and it does not publish the rules it uses, so no practice guarantees a Number stays connected. The patterns below are what Polymorfa sees on the Numbers its customers connect, not WhatsApp policy. Calling only people who expect to hear from you keeps a Number in good standing and lowers the risk. The practices apply to every call a linked-device Number places, whether a browser client, your server code, or a [SIP trunk](/guides/communicate/sip-trunks) places it. ## Start a new Number gradually Numbers that place many calls in their first days are the ones Polymorfa sees restricted soonest. * Start with a small number of messages and calls a day to people you know, and increase the volume a little each day. * Grow further only while people answer your calls and reply to your messages. * While a Number is new, keep it linked to one service. Do not link it to other tools at the same time. ## Call people who already chatted with you Reaching many people for the first time in a short period is the pattern Polymorfa sees on restricted Numbers most often. One Number calling dozens of new people within minutes looks like voice spam, and people who did not expect the call report it. * Call people who have messaged you, or whom you have messaged and who replied. * Contact someone new only when they asked to hear from you, for example by requesting a callback. * Sending one-way commercial messages that nobody answers raises the risk for the Number's calls too, not only for its messages. ## Treat cold calls as the riskiest act Recipients who do not recognize the caller report the call, and reported Numbers are the ones Polymorfa sees restricted. A call to someone who has never interacted with the Number carries the highest risk of a report. * Do not place unsolicited calls or high-volume calls from a linked-device Number. * Do not call the same unknown person repeatedly from the same Number. * Before you call someone new, send a message and wait for a reply. ## Avoid recycled numbers Carriers reissue phone numbers. A number another person used recently can carry their history with WhatsApp and be restricted as soon as you connect it. * Prefer numbers freshly issued by the carrier. * If a new Number receives messages or calls from people you do not know in its first days, a previous owner probably used it. Choose another number before you place calls from it. ## Lower volume in sensitive periods Restrictions are more common around events such as elections, political campaigns, and media crises. In those periods, place fewer calls, limit them to people who expect them, and watch your Numbers more closely. ## Monitor every Number * Watch each Number's connection and call results. Repeated declined or missed calls to new contacts show that people do not expect your calls. Stop calling new contacts from that Number and review how you choose who to call. * The Number's [BanSafe telemetry](/guides/bansafe/telemetry) counts the calls it placed, how they ended, how many callees had never chatted with it, and how many new people it reached in each hour by message and by call. * Subscribe to `session.restriction_updated` to learn when WhatsApp restricts a Number to people it has already chatted with, and when that restriction ends. See [Webhooks](/api/webhooks#number-restrictions-and-logouts). * Use [`callsEnabled`](/guides/communicate/calls#turn-calling-off-for-a-number) to stop a Number's calls without disconnecting it while you investigate. ## After a restriction or ban * Stop the calling that led to the restriction, and change how you choose who to call, before you place calls from this or any other Number. * While WhatsApp restricts a Number to people it has already chatted with, Polymorfa refuses calls to anyone else with [`number_restricted`](/api/errors#number-restricted) instead of placing them, and a call WhatsApp refuses ends with `reason: "call_restricted"`. * If you believe WhatsApp restricted or banned the Number in error, request a review through WhatsApp's appeal process. * Use a replacement Number only as WhatsApp's terms allow. Do not use a new Number to continue the calling that was restricted. * Move business-initiated calling at volume to a Cloud API Number, as described below. ## Use Cloud API Numbers for business-initiated calling at volume For calls your business starts at volume, such as callbacks, appointment calls, or outreach campaigns, connect a Number through the WhatsApp Business Cloud API. Before a Cloud API Number calls someone, the recipient grants your business permission to call them, so every call reaches a person who agreed to it. Business-initiated calling on a Cloud API Number follows Meta's own availability requirements for that Number, including the country of its phone number. Confirm with Meta that your Number qualifies before you move calling to it. Cloud API calls are one-to-one and audio only. See [Cloud API Numbers](/guides/communicate/calls#cloud-api-numbers) for how calls work on them, and [Connection methods](/console/sessions#connection-methods) for the ways to connect a Number.