Business Phone Number Types: Local, 03, 0800 or Toll-Free?
Business Phone Number Types: Which Numbers Should a Small Business Use?
Tom Reed · Updated 9 October 2026
Most small businesses need one local number as their main line, plus an 0800/toll-free or 03 number only if callers expect free or flat-rate calls. Pick numbers by who calls you and what they pay, get them from your SIP carrier, then give each number its own route (person, ring group, queue or call flow) on your phone system. This playbook covers which business phone number types exist in the UK and US, what each tells a caller, what it costs them, and how to route each one.
What types of business phone number are there?
As of October 2026, Ofcom's phone numbers and call costs page splits UK numbers into a few families; in the US, the FCC's toll-free guide separates toll-free codes from local numbers.
UK geographic numbers (01 and 02). Ofcom says geographic numbers "start with 01 or 02 and are linked to a specific area" through the area code, such as 0131 for Edinburgh or 020 for London.
UK 03 numbers, including 0333. These are non geographic numbers: not tied to a town. Ofcom says it introduced UK-wide 03 numbers "as an alternative to chargeable 08 numbers" so organisations can have "a single national point of contact without consumers having to pay extra to call them". 0300, 0333 and 0345 are all in this range.
UK 080 Freephone (0800 and 0808). Ofcom describes 080 numbers as "free to call". An 0800 number is the classic free-to-call business line.
UK 084 and 087 service numbers. Ofcom notes that numbers "such as 084, 087 and 09" "might be charged extra". Few small businesses need one today.
UK mobile numbers (07). Ofcom says mobile numbers start with 07. Note that 070 numbers are personal numbers, not mobiles, and Ofcom warns calls to them "can be more expensive".
US local numbers. An ordinary number with a local area code.
US toll-free numbers. The FCC lists seven toll-free codes: "800, 888, 877, 866, 855, 844 and 833". They "are not interchangeable": the same seven digits after 800 and after 888 reach different subscribers. That's what most people mean by a toll free number for business.
Which number type suits which kind of small business?
Choose by who calls you, from where, and what they expect to pay. Caller costs are from Ofcom and the FCC as of October 2026; your carrier sets what you pay.
| Number type | Signals to callers | Caller cost (as of October 2026) | Best for | Route to |
|---|---|---|---|---|
| UK local (01/02) | A real office in a named area | Usually inside call packages; Ofcom's call costs guide says costs vary by plan | Main line for most local and regional firms | Reception ring group or a short menu |
| UK 03 (0300/0333/0345) | One national number, not tied to a town | No more than a call to 01/02, and counts towards inclusive minutes (Ofcom) | National service or support lines; multi-site firms | Support queue or call flow |
| UK Freephone (0800/0808) | Free to call; customer-first | Free from consumer landlines and mobiles; business callers should check with their provider (Ofcom) | Sales lines and consumer helplines | Sales ring group or queue |
| UK 084/087 | A service number | Access charge plus a service charge set by you (Ofcom) | Rarely a good choice for a new SMB line | Review before keeping |
| UK mobile (07) | A person rather than an office | Often inside call packages; outside them, charged by plan (Ofcom) | Individual staff on the move | That person's apps |
| US local | A local business in that area code | Depends on the caller's own plan | US presence; area-specific campaigns | US team ring group |
| US toll-free (800, 888, 877, 866, 855, 844, 833) | National US business; free to call | No charge from landlines; wireless callers pay airtime unless on an unlimited plan (FCC) | US customer service and sales | US queue or call flow |
Three patterns cover most small teams:
- Local service business (trades, clinics, agencies): one local 01/02 number as the main line, plus direct dials where needed.
- National or online business: a local office number plus an 0800 number (free for consumers) or an 03 number (flat national rate) for customers.
- UK firm selling into the US: keep the UK main line and add a US local or toll-free number routed to whoever covers US hours.
Keep the count low: every extra number must be published, routed, tested and paid for.
What does each number cost the caller and you?
Ofcom says actual costs "depend on your communication provider", the plan, time of day and the number called, so this section sticks to rules, not prices.
Calls to 01 and 02. Ofcom says calls to these numbers from mobiles are "typically" included in free call packages.
Calls to 03 (including 0333). Ofcom's rule: "Calls to 03 numbers cost no more than a national rate call to an 01 or 02 number and must count towards any inclusive minutes in the same way as 01 and 02 calls." That applies from "any type of line including mobile". Revenue sharing on 03 calls isn't allowed.
Calls to 0800 and 0808. Ofcom: "Calls are free of charge from all consumer landlines and mobile phones." If the caller is another business, Ofcom says they "should check with your provider whether there will be a charge".
Calls to 084 and 087. The caller pays an access charge to their own phone company plus a service charge set by the organisation they call. If you inherited one, decide whether it still fits.
Calls to US toll-free numbers. The FCC says they can be dialled "from landlines with no charge to the person placing the call", while "wireless callers, however, will be charged for the airtime minutes used during a toll free call unless they have an 'unlimited calling' plan".
What you pay. Your carrier sets number rental, inbound charges on free-to-call numbers and outbound rates. Get them in writing before you print a number.
Do you need a virtual phone number for your business?
A virtual phone number for business is a number that isn't tied to a physical line or desk. Calls arrive through a SIP trunk and ring whichever apps or phones your routing chooses. On a cloud phone system almost every number is virtual, so the real questions are:
- Do you need a second number at all? If one local main line plus extensions covers every caller, you don't.
- Do you need a number in another place? A US local number for a UK firm gives callers a local option without an office there. Check your carrier's rules for numbers outside your area.
- Do you need to keep personal mobiles private? A business number on staff apps lets people call from their own phones without sharing their mobile number.
For the wider architecture, see what a cloud-based phone system is and how a PBX phone system handles call control.
Where do business numbers come from?
Numbers come from a carrier, not your phone system. Keep three layers separate:
- The SIP carrier supplies the numbers, carries external calls and bills you for both.
- The SIP trunk connects those numbers to your phone system.
- The phone system (hosted PBX) decides who rings, what callers hear and where unanswered calls go.
SessionPBX sits in layer 3. Its hosted PBX page says you "connect the SIP trunk you already use — any SIP-compliant carrier works", and that "your carrier bills you for numbers and calls". SessionPBX doesn't supply numbers, port them or provide lines; pick a carrier that offers the number types and countries you need, then connect its trunk.
Keeping existing numbers. Ofcom says you "can usually keep your phone number when you switch provider", and that in most cases you can request the transfer "for up to one month after your previous service ends". Port first, cancel last. In the US, the FCC's porting guide says you can keep your number if you stay in the same geographic area, and warns: "Do not terminate your service with your existing company before initiating new service with another company." The FCC also requires toll-free numbers to be portable to a new RespOrg (the company that manages toll-free records).
Inventory every number first. The UK porting guide covers the UK process in depth, and the porting checklist gives a cutover runbook for UK and US.
How should each number route on your phone system?
Give every number a purpose, an owner and a route:
- Main local number: reception ring group, or a short menu (sales, support, accounts) in front of it.
- 0800 sales line: the sales ring group, with a named overflow and voicemail that someone owns.
- 03 support line: a support queue with a maximum wait and an overflow destination.
- US number: the people covering US hours, with business-hours routing in the right time zone.
- Direct dials: the person, then their voicemail.
- Legacy or campaign numbers: a deliberate destination.
On SessionPBX, the hosted PBX page says you can "give each inbound number its own route to a person, group, queue or call flow". Teams Business adds the visual call flow designer, IVR menus, business-hours routing per day with your time zone, ring groups, call queues and call recording. Voicemail can arrive by email with the recording attached, and missed-call notifications show who needs a call back.
For ring and hunt patterns per number, use the call routing guide. If you're still writing the requirement, the phone system requirements checklist shows how to map each number to a purpose, owner and destination.
How do you choose your outbound caller ID per number?
Outbound caller ID is the number people see when your team calls them. Get it wrong and customers call back a number that rings nobody.
Use a number that rings back. In the UK, Ofcom's caller ID guidance says that where caller ID is provided, it "must include a valid, dialable telephone number which uniquely identifies the caller". Only present numbers you're entitled to use.
Match the caller ID to the job. Sales present the sales number, support the support line, US staff the US number. Account managers may prefer their direct dial.
On SessionPBX, the hosted PBX page says you can "set each member's outbound caller ID from your connected numbers". Which numbers you may present is up to your carrier, so confirm it with them.
What about 0333? An 0333 number is a standard 03 number with the same cost rule as 01 and 02. Whether calls get answered depends more on whether callers recognise the number, so publish it consistently and make sure it rings back to a real route.
Business phone number checklist
Put an owner and a date next to each step.
- List who calls you: customers, suppliers, partners, and which countries they're in.
- Pick one main local number (01/02, or a US local number for a US-only business).
- Decide whether you need a free (0800/toll-free) or flat-rate (03) line, and for which callers.
- Check that your carrier covers the number types and countries you need, in writing, with rates.
- Port existing numbers first; don't cancel an old line until its number has moved.
- Map each number to a route: person, ring group, queue or call flow.
- Set out-of-hours routing for every number, not just the main line.
- Set each member's outbound caller ID from your connected numbers.
- Test every number from a mobile and a landline: inbound, out-of-hours, voicemail and call back.
- Publish numbers consistently on your site, email signatures and Google Business Profile.
When your carrier and numbers are lined up, set up SessionPBX with your SIP trunk, give each number its route, and try the SessionTalk softphones on desktop and mobile.
FAQ
Is an 03 number cheaper for callers than 0800?
No. As of October 2026, Ofcom says 0800 and 0808 calls are free from consumer landlines and mobiles, while 03 calls cost no more than an 01 or 02 call and count towards inclusive minutes. See Ofcom's call costs guide.
Can I keep my existing number when I change phone system?
Usually, yes, by porting it to your new carrier. Ofcom says you can usually keep your number when you switch provider. Follow the UK porting guide and the porting checklist, and keep the old service live until the port is confirmed.
Can one phone system handle UK and US numbers?
A hosted PBX routes the numbers that arrive on its SIP trunk, so it's mostly a carrier question. Ask whether your carrier offers numbers in both countries, then give each number its own route and caller ID.
Do 0333 numbers look like spam?
Not inherently. 0333 is part of Ofcom's 03 range and costs callers no more than an 01 or 02 call. Whether people answer depends on recognition, so use the same number everywhere and make sure it can be called back.
Does SessionPBX supply phone numbers?
No. SessionPBX is the hosted phone system. Your SIP carrier supplies numbers and bills you for numbers and calls, and you connect its trunk to SessionPBX.
