Step 1: Check the number
Look at the full number and call details on your bill:
- date and time of the call
- call duration
- cost
This can help you identify the call.
Step 2: Check with people who use your phone or account
Ask anyone who may have used your phone, such as:
- family members
- friends
- visitors
Some calls may have been made without you realising.
Step 3: Check common reasons for unknown numbers
The number may be:
- a service or customer support line
- an automated call (such as voicemail or call divert)
- a premium-rate or international number
- a number is stored differently in your contacts
Step 4: Check your call settings
Check if any features are active:
- Voicemail
- Redial or automatic services
If you still don’t recognise the number
Contact us, and we’ll help you check the charge.
Please give us:
- the number.
- The date and time.
- The charge on your bill.
If you think the charge is wrong
- contact us as soon as possible
- we’ll investigate and explain the charge
You can get more detailed information about calling prices from a BT line in the BT Tariff Guide (PDF).
Use this table to help you recognise a number from your bill:
| Number | Use |
|---|---|
| 00 | Access for international calls |
| 01 | National geographic numbers in the UK |
| 02 | National geographic numbers in the UK |
| 03 | National non-geographic numbers with calls charged at or below rates for geographic numbers |
| 04 | Not used |
| 0500 | Numbers that are free to call |
| 055 | Corporate numbers |
| 056 | Location Independent Electronic Communications – typically VoIP services |
| 06 | Not used |
| 070 | Personal numbers |
| 076 | Radio paging calling |
| 071-075 & 077-079 | Mobile telephones |
| 0800 & 0808 | National numbers that are free to call |
| 0820 | National numbers for Internet for school services |
| 0844 | Service numbers that consist of an access charge from BT, plus a service charge set by the company you call |
| 0845 | Service numbers that consist of an access charge from BT, plus a service charge set by the company you call |
| 0870 | Service numbers that consist of an access charge from BT, plus a service charge set by the company you call |
| 0871 & 0872 | Service numbers that consist of an access charge from BT, plus a service charge set by the company you call |
| 090, 091 & 098 | Premium Rate Services. Service numbers that consist of an access charge from BT, plus a service charge set by the company you call |
| 100 | Operator |
| 112 | Emergency assistance |
| 118xxx | Directory Enquiries. Service numbers that consist of an access charge from BT, plus a service charge set by the company you call |
| 141 | Dialling 141 before you dial a number means that your number will be withheld. This service is called blocking your calling line identity (CLI) |
| 2-8 | Not used in the National Number Plan, but may be used for local dialling to geographic numbers and as ‘short codes’ from mobile telephones |
| 999 | Emergency assistance |