Customers won't answer unfamiliar numbers
Calling from a mobile number or an unverified line makes customers hesitant to answer for fear of scams—and the opportunity is lost.
SIP Trunk & DID Number
Business DID NumbersDelivered over SIP Trunk
Direct business numbers from NT connect to your Cloud PBX or IP PBX over the internet, with fast activation and capacity that scales with your business.
- Direct NT business numbers
- Whoscall Verified Number
- PDPA-aligned service
- Trusted by 4,600+ organizations
Traditional phone systems are holding your business back
Physical wiring is a hassle
Traditional copper lines require new cabling every time you add a line or move offices—slow and expensive.
Contact numbers go unmanaged
Employees rely on personal mobile numbers to reach customers. The organization loses control, looks less professional, and loses contact history when staff leave.
Expansion means changing numbers
Moving offices or opening a new branch usually means a new number. Existing customers can't reach you, costing time and business continuity.
What Are SIP Trunk and DID Numbers?
Call On Cloud provides direct NT business numbers over SIP Trunk, connecting your Cloud PBX or IP PBX to the public telephone network without traditional copper lines.
Voice connectivity over the internet
SIP Trunk connects your PBX to the public telephone network over the internet. Add or reduce concurrent calls without installing new lines or hardware.
Direct numbers for teams and departments
DID numbers let customers reach a person or department directly. Assign separate numbers to sales, service, or finance while maintaining a professional business identity.
Diagram
Core SIP Trunk and DID Number Capabilities
Direct DID numbers
Assign business numbers to teams, services, or call flows.
Concurrent call capacity
Choose how many inbound and outbound calls can run at the same time.
PBX compatibility
Connect supported Cloud PBX and IP PBX systems.
Number scalability
Add numbers as new branches, departments, or campaigns are launched.
Call forwarding
Create backup destinations to reduce missed calls during connectivity incidents.
Verified business calling
Discuss available caller-identification options such as Whoscall Verified Number.
Whoscall Verified Number
Verify Your Business Number with Whoscall
Whoscall Verified Number displays your company name, logo, and verification badge on outgoing calls, helping customers recognize and answer your business number.
- Higher answer rates—customers see your company name clearly and answer with confidence, so important calls don't go unanswered.
- Protection against caller-ID spoofing—the Verified badge distinguishes your genuine business number from numbers scammers fake.
- Stronger brand trust—every outbound call becomes an official brand touchpoint, ideal for sales, follow-ups, and customer service.
- Works instantly with DID Number—add it to any Call On Cloud 02 number.
Questions IT and Procurement Teams Ask
Choosing a business number means choosing a long-term service provider. More than 4,600 organizations trust Call On Cloud.
QCan we trust the assigned number?
Direct NT numbers, not add-on numbers
Numbers are issued directly by the national telecom provider for stable, compliant long-term business use.
QWhat happens if the service goes down?
99.9% SLA on AWS Bangkok
High Availability infrastructure runs around the clock, with automatic forwarding to a backup number.
QIs customer call data secure?
Encrypted calls, Thailand data residency, PDPA aligned
Voice traffic is encrypted, access is controlled, and service data remains in Thailand.
QWho supports us when there is a problem?
Local support from setup through after-sales
A Thai specialist team handles installation, troubleshooting, and ongoing service without overseas ticket delays.
QWill we need another system as we grow?
Scale with one service provider
Start with DID numbers and expand to Cloud PBX, recording backup, and Voice AI in the same ecosystem.
QDo you have proven experience?
Trusted by more than 4,600 organizations
Businesses, enterprises, and public-sector organizations use Call On Cloud communication services.
Memorable VIP Numbers for Your Business
Choose a number that is easy to remember and reinforces your business identity across every customer touchpoint.
Diamond Crown
100,000 THB
90,000THB
Diamond
30,000 THB
27,000THB
Platinum
20,000 THB
10,000THB
Gold
5,000 THB
4,500THB
| Number | Level | Price |
|---|---|---|
| 02-028-7777SOLD OUT | Diamond Crown | 100,00090,000 THB |
| 02-028-7766 | Diamond | 30,00027,000 THB |
| 02-109-4242 | Diamond | 30,00027,000 THB |
| 02-028-7770 | Platinum | 20,00010,000 THB |
| 02-109-4200 | Platinum | 20,00010,000 THB |
| 02-028-7702 | Gold | 5,0004,500 THB |
| 02-109-4212 | Gold | 5,0004,500 THB |
Sample numbers only. Availability is updated from the live inventory and prices exclude VAT.
Transparent Usage-Based Pricing
Start with the numbers and concurrent calls you need, then expand at any time.
DID Number
A business 02 number sourced directly from NT
100THB / number / month
- Legally issued 02 number
- Works instantly with Cloud PBX / IP PBX
- Add as many numbers as you need
- Number Portability supported
Concurrent Call
Simultaneous inbound/outbound call channels
80THB / channel / month
- Scale channels to match call volume
- Built for high-traffic call centers
- Adjust up or down each billing cycle
- No new wiring or equipment required
Call Rate
Outbound call rates billed on actual usage
0.80THB / minute*
- Mobile & long-distance: THB 0.80/min*
- Local landline: THB 3/call*
- No hidden fees
- Usage reports available for review
*Call rates vary by destination. All prices exclude VAT. Contact our sales team for an official quotation.
Which Businesses Benefit Most from SIP Trunk and DID Numbers?
Use Case
Contact centers
Provide sufficient call channels and direct numbers for service queues.
Use Case
Hybrid organizations
Keep one professional calling identity across offices and remote teams.
Use Case
Sales operations
Allocate trackable numbers to teams or campaigns and connect calls to CRM workflows.
Frequently Asked Questions
How does a DID number differ from an ordinary phone number?+−
A DID number runs over the cloud and SIP Trunk, so it is flexible, easy to scale, and does not depend on traditional phone lines. Customers can reach the employee or department they want directly, without going through an operator.
What is a concurrent call, and how many do we need?+−
It is the number of calls that can be active at the same time — a 5 CC plan handles up to five simultaneous inbound or outbound calls. Capacity can be increased as needed, up to the number of extensions you have, and our team can help size it to your call volume.
Can we move an existing number from another provider?+−
Yes, through number portability, with no change to your number. The number must be in SIP Trunk form; if it is still analog, upgrade it to SIP Trunk with your current provider first and then move it over.
If the internet goes down, will we miss important calls?+−
You can set call forwarding to a backup number — for example, automatically diverting calls to a mobile — so your business does not miss important contacts even when the office internet is down.
Is call data secure and PDPA-compliant?+−
Voice traffic is encrypted and access is tightly controlled. The system is hosted on AWS Bangkok, so data stays in Thailand, and it is designed to align with Thailand's Personal Data Protection Act (PDPA). Voice Record Backup is available as an add-on for storing conversation recordings.
What is Whoscall Verified Number, and is it a separate subscription?+−
It is a business number verification service that shows your company name, logo, and a Verified badge on the recipient's screen for every outbound call, raising answer rates and preventing scammers from impersonating your number. It can be added to any Call On Cloud DID number.
Why use numbers from NT?+−
Call On Cloud numbers come directly from NT (National Telecom Public Company Limited) and meet international standards — not secondary numbers that may be less stable. You get signal quality, legal correctness, and long-term usability.
Is there an SLA for reliability?+−
Yes — a 99.9% SLA on high-availability AWS Bangkok infrastructure, available 24 hours a day, with automatic call forwarding to a backup number so your business does not miss important calls.
