The dial string is +91 followed by the 10-digit Indian number with the leading 0 dropped. Indian toll-free numbers, anything starting 1800, 1860, or 1075, are domestic only and will not connect from a UK number. Indian mobiles dominate; landlines outside the top six cities are mostly inactive.
The dial string
To call India from the UK, dial:
- ›+91 {area code or mobile prefix} {number}, or
- ›00 91 {area code or mobile prefix} {number} from a UK landline that prefers the international access prefix.
Drop the leading 0 from the Indian number. A Bengaluru mobile printed as 09876 543210 is dialled as +91 98765 43210. A New Delhi landline printed as 011 2345 6789 is dialled as +91 11 2345 6789.
The carrier-specific international dialing prefixes (00, 001, 0011) that older guides recommend are an artefact of British Telecom's pre-2008 routing. Every UK carrier today resolves + and 00 identically.
Mobile vs landline
Indian mobile numbers are 10 digits starting 6, 7, 8, or 9. Mobiles account for over 95% of active Indian numbers; if you have a 10-digit number with no separator, it is almost certainly a mobile.
Indian landlines vary by city. The STD (Subscriber Trunk Dialing) code is 2 digits for the largest cities (Mumbai 22, Delhi 11, Bengaluru 80, Chennai 44, Kolkata 33, Hyderabad 40), 3 digits for tier-2 cities (Pune 20, Ahmedabad 79), and up to 4 digits for smaller towns. The subscriber number is 6-8 digits depending on the city's exchange.
India does not bill the receiver for incoming international calls. Whoever you are calling pays nothing for your call.
What it costs
Four realistic routes for a UK→India call in 2026:
- ›UK mobile international add-on. Vodafone UK's Stay Connected pass and EE's Roam Like at Home both exclude India from their standard inclusive plans; per-minute rates without an add-on sit at £1.00, £1.50/min to Indian mobiles. (See your carrier's international rate sheet.)
- ›Pre-paid international calling card. £5, £10 cards aimed at the South Asian diaspora advertise sub-1p rates to India. The advertised rate excludes the connection fee and short-call rounding, which often doubles the effective price on calls under 5 minutes.
- ›VoIP app-to-phone. Skype's successor Microsoft Teams Phone and Viber Out both terminate calls to Indian mobiles at around £0.025/min, charged from a pre-paid balance. Both require app installation and account creation.
- ›Browser-to-phone via WorldDial. £0.019/min to Indian mobiles, £0.013/min to Indian landlines, billed per minute, rounded up. No app, no SIM, works from any browser.
If you call India for more than 10 minutes a month, the UK carrier add-on loses to all three alternatives. For short, frequent calls, the per-second billing of a browser-to-phone service usually beats a pre-paid card's connection fee.
Toll-free numbers from this corridor
Indian toll-free numbers start 1800 (and 1860, 1075). They are funded by the Indian called party and routed exclusively through the Indian domestic toll-free network. They will not connect from a UK number on any carrier or app.
Most Indian banks and government services that publish a 1800 number also publish a separate paid international number on the same contact page, usually a Mumbai or Delhi landline (+91 22 … or +91 11 …). HDFC Bank's international card-services line is +91 22 6160 6161; State Bank of India publishes +91 22 2274 7606. Passport Seva's Hyderabad paid numbers are not a general overseas helpline; overseas renewals go through the embassy Passport Seva portal. Always look for the paid international number when the toll-free one is the only one your search returned.
Best calling windows
India Standard Time is UTC+5:30. UK time is UTC+0 (winter) or UTC+1 (BST, summer). India runs 5h30 ahead of UK in winter, 4h30 ahead in summer.
Indian banks, government offices, and telcos do not publish quietest-hour data, so this guide does not guess one. Work from the opening hours on the contact page for the line you need. Indian late morning, 10:00-12:30 IST, is 04:30-07:00 GMT or 05:30-08:00 BST, which means an early alarm in the UK.
Indian afternoon, 14:00-16:00 IST, maps to 08:30-10:30 UK morning. Many offices break for lunch shortly before that.
Pitfalls specific to this corridor
- ›Aadhaar and bank IVRs require Indian-mobile OTP. Most Indian banks and government services route identity verification through SMS to a registered Indian mobile number. If you call from the UK to dispute a transaction or request a password reset, the agent will offer to send an OTP to your registered Indian mobile, if that SIM is in a drawer at your parents' house in Bengaluru, the verification fails. Plan for this before you call: keep an Indian eSIM or a forwarding service active.
- ›DTMF delivery on VoIP routes is inconsistent. Indian bank IVR menus are deep, 4-6 levels, and require touch-tone (DTMF) input that some VoIP-to-PSTN bridges deliver imperfectly. The symptom is the IVR repeatedly saying "Sorry, I didn't catch that." WorldDial supports clean DTMF; test on the menu before a long call.
- ›Indian regulators throttle some international VoIP termination. TRAI's rules on international long-distance carriers mean that VoIP-to-PSTN calls land via a small set of approved gateways. Some carriers see intermittent silent-audio issues on outbound legs to Indian landlines. If a call connects and the line is silent, hang up and redial; the second attempt usually routes via a different gateway.
- ›WhatsApp calling is not a reliable replacement. WhatsApp voice calls have been intermittently blocked or throttled at the network layer by several Indian ISPs since 2023, especially during political events. If you need to reach a phone number that is not on WhatsApp (most Indian banks, all government offices), only the PSTN route works.
Quick checklist
- ›Have the destination number in international format: +91 followed by 10 digits.
- ›Drop the leading 0 from the Indian number before adding +91.
- ›Pick a window that hits Indian office hours: aim for 10:00-12:30 IST.
- ›Have your reference number, customer ID, and Indian-mobile-linked OTP ready before dialing.
- ›Use a per-minute paid route; the toll-free 1800 numbers will not connect.
Need to call a real phone number?
Open WorldDial, enter the number, and check the live rate before you dial. Pay as you go from your browser. The other person does not need an app.
Pay as you go • No subscription required • Recipient does not need WorldDial
FAQs
What is the international dialing code for India?
+91. From the UK, dial +91 or 00 91, then the 10-digit Indian number with the leading 0 dropped.
Can I dial Indian 1800 toll-free numbers from the UK?
No. Indian 1800 and 1860 toll-free numbers are domestic-only. The international carrier has no way to bill the call back to the Indian toll-free provider, so the call either rings forever or returns a "this call cannot be completed" tone. Look for the paid international number on the same contact page, usually a Mumbai or Delhi landline.
What's the cheapest way to call India from the UK?
Browser-to-phone services bill per second at around £0.019/min to Indian mobiles. Pre-paid calling cards advertise lower rates but include connection fees that double the effective cost on calls under 5 minutes. UK carrier international add-ons remain the most expensive route, usually 50-80x the per-minute cost of the alternatives.
Will WhatsApp work for my India call?
Only if the person you are calling is on WhatsApp and is willing to take a voice call there. Government offices, banks, and most institutions in India do not run WhatsApp lines for customer service. Several Indian ISPs throttle WhatsApp calls at the network layer during politically sensitive periods. For a phone number, you need a phone-network call.
Why does the call connect but I hear nothing?
The most common cause on this corridor is a one-way audio failure on the outbound leg through an Indian gateway. Hang up immediately and redial, the next call usually routes via a different gateway. If the silent-audio failure repeats three times, try a different calling route or app entirely.