Numbers And BYOC

Documentation Index

Fetch the complete documentation index at: https://support.callin.io/llms.txt

Use this file to discover all available pages before exploring further.

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Overview

Phone numbers are the bridge between your AI agents and real phone calls. In Callin.io, you’ll manage this in two places:

• Numbers: Buy numbers through Callin.io, import from providers, or verify a personal number.
• BYOC (SIP Trunk): Bring your own carrier by connecting Telnyx or any SIP provider.

Use these shortcuts to jump straight into the app:

• Go to Numbers: Open Numbers
• Go to BYOC (SIP Trunk): Open BYOC

Tip: If you’re getting started quickly, buy a US/Canada number (instant). If you need an international number, be ready to submit documents (country rules vary).

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Numbers

The Numbers page shows every number connected to your workspace (purchased, imported, personal, Telnyx, or BYOC). From here, you can add new numbers and confirm each number’s status.

Screenshot: The Numbers page where you can filter by provider and click + Add Number to purchase or import numbers.

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What you can do in Numbers

When you click + Add Number, you’ll typically see these options (wording may vary slightly by account/plan):

• Purchase Number (buy through Callin.io)
• Import from Twilio
• Add Personal Number
• Add Telnyx Number (after Telnyx is connected)

You’ll also usually see filters like Purchased, Twilio, Personal, Telnyx, and BYOC (SIP Trunk) to quickly find what you’re looking for.

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Option A: Purchase a number through Callin.io

Buying numbers through Callin.io is the simplest way to get started.

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US & Canada: instant purchase

For United States and Canada, the purchase flow is typically instant:

1. Go to Open Numbers.
2. Click + Add Number → Purchase Number.
3. Choose the Country.
4. Choose a type:
   • Local
   • Toll-Free (if available)
5. (Optional) Use Search by Area Code (example: 415).
6. Click Search Numbers.
7. Select a number from the list.
8. Click Purchase Selected Number.

Important: After purchase, the number should appear in your list. If you see a warning like “this number is not assigned to any agent,” you still need to assign it to an agent before using it.

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Other countries: request + documentation

Captura: after you start the request, the platform loads the country-specific fields and documents you must complete before payment and review.

For many non-US/Canada countries, purchasing is a request-based flow rather than an instant checkout.

• You select the country and number type (for example Local or Mobile).
• You may see Request Type options such as New number and Porting.
• You choose one of the available numbers and click Start request.
• The platform then loads the country-specific information and documentation requirements.
• You must complete the required fields, upload documents, and save each item.
• You submit the request, pay any required fees, and then the request is reviewed by an operator.

You can typically track these under a tab like Number Requests. This part of the process is important because the requirements are not always the same. They can change depending on the country, the number type, and whether the request is being made by an individual, a sole proprietorship, or a company.

How the documentation step works

After you click Start request, the form may show a combination of:

• Text fields you must complete manually
• Upload fields for supporting documents
• A Save button for each individual requirement
• A Pending status until that specific item is correctly saved or uploaded

This means the request is usually completed piece by piece, not all at once. If a field or upload still shows Pending, that requirement is normally not complete yet. In many request-based countries, the form can ask for details such as:

• Identity document type
• Identity document number
• Date of birth
• Place of birth
• Identity document issuer
• Identity document expiration date
• Local address in the same country
• Personal Tax Code
• VAT number
• Company Tax Code
• IT Customer Type
• Proof of Address
• Passport/ID copy
• Company Registration certificate

Some labels may also clarify who must provide each item, for example:

• For legal entities only
• For legal entities and sole proprietorships only
• For natural persons and sole proprietorships only

So, even if two customers request numbers in the same country, the required documentation may differ depending on the business type and the exact number category.

Tip: In the request form, some fields have their own Save button. Entering a value is not always enough by itself. The item may continue to show Pending until you click Save successfully.

Common document requirements (examples)

Exact requirements depend on the country and number type, but you may be asked for items like:

Proof of address: what usually causes problems

The proof of address document is one of the most common reasons a request is delayed. In many countries, the uploaded proof of address must meet all of these conditions:

• It must clearly show the same name used in the request, or the company name if the request is for a business
• It must clearly show the same address entered in the form
• It must be recent
• It must be complete and readable
• It must not be cropped in a way that hides important details

A very important rule is that the bill or address document often must be no more than 3 months old at the time of submission. That usually means you should upload a recent document such as:

• A utility bill dated within the last 3 months
• A bank statement dated within the last 3 months
• An official government or tax letter dated within the last 3 months

Older documents may be rejected even if the address itself is correct.

Important: When you upload a bill or bank statement as proof of address, make sure it is less than 3 months old. If the document is older, the request may remain pending or be rejected during review.

How to prepare documents before uploading

To avoid delays, check each document before you upload it. A good document should be:

• Clear and readable
• Complete, not cut off at the edges
• Consistent with the data entered in the form
• Current, especially for address documents
• Relevant to the requester type, whether individual or company

For example, if the request is for a company, the reviewer may expect the company name, company number, tax details, and registration documents to match each other. If the request is for an individual, the reviewer may check that the personal name, ID document, and proof of address all match. Common issues that can slow approval include:

• The address in the form does not match the uploaded document
• The uploaded bill is older than 3 months
• The passport or ID copy is blurry
• A company request is submitted with personal documents only
• A field is filled in, but the user did not click Save
• A document was uploaded, but its status still shows Pending

Common mistake: Uploading the correct file is not always enough. After each upload or text entry, check that the requirement no longer shows Pending.

Fees + review

Some countries show a fee payment step after the documentation is completed. This may include:

• A one-time activation fee
• The monthly recurring cost for the number

The request generally moves forward only after the required documents are uploaded and the payment step is completed. After you submit and pay:

• You’ll receive a Request ID
• The request is reviewed by an operator
• Once approved, the number appears in your Numbers list

The review is manual in many cases, which is why approval is not always immediate.

Important: Approval timing can vary by country, provider rules, and document quality. If you need the number for an upcoming launch or campaign, submit the request as early as possible and use recent, clearly readable documents.

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Option B: Import numbers from Twilio

If you already own numbers in Twilio, you can import them into Callin.io:

1. Go to Open Numbers.
2. Click + Add Number → Import from Twilio.
3. Enter your Twilio Account SID and Twilio Auth Token.
4. Click Search Twilio Numbers and select the numbers to import.
5. Assign imported numbers to an AI agent when you’re ready to use them.

Common mistake: Copying the wrong Twilio credentials (for example, using a test credential instead of live). If no numbers appear, re-check your Twilio project and permissions.

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Option C: Add a Personal Number (outbound-only)

A Personal Number is useful when you want to place outbound calls from your own phone number—but it cannot receive inbound calls inside Callin.io.

Screenshot: The Add Personal Number modal with phone input and the verification process (you receive a verification call and enter the code).

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Verify your personal number

1. Go to Open Numbers.
2. Click + Add Number → Add Personal Number.
3. Select your country code and enter your phone number.
4. Click Verify Number.
5. You’ll receive a verification call.
6. Enter the verification code when prompted.
7. After verification, the number is added to your account.

Important: Personal numbers are outbound-only. If you need inbound calls, use a purchased/imported number or BYOC.

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Option D: Add/Import Telnyx numbers

If your Telnyx account is connected (via BYOC), you can import active Telnyx numbers into Callin.io:

1. Go to Open Numbers.
2. Click + Add Number → Add Telnyx Number.
3. Select the Telnyx numbers you want to add/import.
4. Confirm, then assign them to agents as needed.

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Assign numbers to agents (so they can be used)

Buying or importing a number is only step one—your agent still needs to use it. On the Numbers list, if you see a warning like “not assigned to any agent,” assign the number to the right AI agent before going live.

Tip: Keep one “test” number separate from production while you’re iterating on prompts and call flows.

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BYOC (SIP Trunk)

BYOC means Bring Your Own Carrier. Instead of buying numbers through Callin.io, you connect your own telephony provider using a SIP trunk. Typical reasons to use BYOC:

• You already have a carrier contract (enterprise telephony)
• You need custom routing, SBC control, or compliance constraints
• You want to avoid Callin-managed telephony rules by using your own provider

Go here to set it up: Open BYOC

Screenshot: BYOC setup where you can connect Telnyx and synchronize numbers into Callin.io.

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What is a SIP Trunk (simple explanation)

A SIP trunk is a connection between a phone carrier and your calling system. Think of it like a “phone line over the internet” that can handle inbound/outbound calls—often used by businesses.

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Option 1: Connect Telnyx

If you use Telnyx, Callin.io can guide the setup with an API key:

1. Go to Open BYOC.
2. Select the Telnyx tab.
3. Paste your Telnyx API Key.
4. Click Start.

During setup, you’ll typically see steps like:

• Saving the Telnyx API key
• Fetching active Telnyx numbers (DIDs)
• Storing numbers in your Callin.io account
• Provisioning the SIP trunk (inbound + outbound)
• Creating provider phone numbers

Once it completes, your Telnyx numbers should appear under Numbers.

Important: If your Telnyx key doesn’t have permission to read numbers/DIDs, Callin.io won’t be able to fetch them.

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Option 2: Connect another SIP provider (Generic SIP Trunk)

If your provider is not Telnyx, use the Other SIP Provider tab. You’ll typically configure three areas: Basic, Inbound, and Outbound.

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Basic

• Label: A friendly name (example: “HQ SIP Trunk”)
• Phone Number (E.164): Full international format (example: +15551234567)
• You may also see toggles like Supports inbound and Supports outbound

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Inbound

Inbound calls go from the carrier to your system.

• Inbound SBC / FQDN: Your SIP address (example: sip.example.com:5061)
• Transport: Often TLS or UDP
• Media encryption: Enable if your provider supports it

Tip: Inbound often does not require credentials. Many carriers authenticate inbound calls by IP allowlists or trunk configuration.

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Outbound

Outbound calls go from Callin.io to your carrier.

• Outbound SBC / FQDN: Your provider’s SIP server
• Transport and Media encryption
• Username and Password: Your SIP credentials
• Allowed countries (outbound): Often Worldwide or a Custom list

When finished, click Save & Import.

Common mistake: Using the wrong SBC/FQDN or credentials. If outbound calls fail, re-check your SIP username/password and whether your provider requires a specific port or transport.

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Minutes and billing (what to expect)

Billing can have two parts: Callin usage and telephony carrier charges. What you see depends on how you connect numbers.

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Callin compute minutes

Compute minutes represent the time your AI agent is active (listening, processing, responding). This is the core usage metric for AI calling.

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Callin-managed telephony: important billing notice (first-minute billing)

When you place calls using Callin-managed telephony (for example, numbers purchased through Callin.io and routed through Callin’s carrier), you may see a first-minute billing rule:

• Minimum charge is 1 minute
• After the first minute, billing typically follows the actual call duration
• This rule typically does not apply to:
  • Browser test calls
  • Imported own numbering (Telnyx or Twilio imports)
  • External SIP trunk (BYOC)

Important: The exact billing behavior can vary based on your setup and provider routing. If you want to avoid Callin-managed telephony rules, import your own numbers or use BYOC.

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Personal number billing reminder

Personal numbers are outbound-only, and calls made using a personal number can still fall under Callin-managed telephony rules depending on how your account routes calls.

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Troubleshooting

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“I can’t make calls”

• Check that you have at least one active number
• Make sure the number is assigned to an agent
• If using BYOC, confirm your SIP trunk settings are correct (SBC/FQDN, transport, credentials)

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“My personal number isn’t receiving inbound calls”

• That’s expected: Personal Numbers are outbound-only
• Use a purchased/imported number or BYOC for inbound calling

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“My imported numbers don’t show up”

• Re-check credentials (Twilio SID/Auth Token, Telnyx API Key)
• Confirm the numbers are active in the provider account
• Try again and verify you’re using the correct project/sub-account in the provider

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Final note

If you want the fastest setup, start with a US/Canada number purchased in Callin.io. If you need advanced routing or already have a carrier, connect BYOC. Once your number is added and assigned, your AI agents can place and receive real phone calls at scale.