How to call the US from the United Kingdom in 2026

The dial string is +1 followed by the 10-digit US number (area code + subscriber number). Many US toll-free prefixes (800, 888, 877, 866, 855, 844) fail or misroute from the UK. For the IRS and Social Security, use the published international numbers, not the domestic 1-800 lines printed on letters.

The dial string

To call the US from the UK:

• ›+1 {area code} {number}, or
• ›00 1 {area code} {number} from a UK landline.

There is no leading zero to drop on standard US numbers. A New York number printed as (212) 555-0142 becomes +1 212 555 0142. A Los Angeles number (310) 555-0199 becomes +1 310 555 0199.

Mobile vs landline

US mobiles and landlines share the same 10-digit NANP format. You cannot reliably tell mobile from landline by looking at the number. Area codes are three digits; major examples include New York 212/646/917, Los Angeles 310/424, Chicago 312/773, Houston 713, Miami 305/786.

The US does not bill the receiver for ordinary incoming international calls.

What it costs

Four realistic routes for a UK→US call in 2026:

• ›UK mobile international add-on. EE’s International Pass and similar Vodafone/O2 bundles cover many US destinations more cheaply than raw pay-as-you-go; without a pass, EE Zone pricing for the US has historically been measured in pounds per minute on standard tariffs (check the current EE price guide before relying on pay-as-you-go).
• ›Pre-paid international calling card. Low headline rates to US landlines; connection fees punish short IVR calls.
• ›VoIP app-to-phone. Teams Phone and Viber Out terminate to US numbers at low single-digit US cents per minute on many routes.
• ›Browser-to-phone via WorldDial. From $0.03/min to US destinations on the public rates table, see call the USA for country context.

For holds longer than about 10 minutes on IRS or bank IVRs, per-minute browser or VoIP routes beat UK carrier pay-as-you-go unless a cheap US-inclusive pass is already active.

Toll-free numbers from this corridor

US 800/888/877/866/855/844 numbers are provisioned for North American origination. From the UK many return “not available from your location” or ring forever. Use the geographic or international line the institution publishes:

• ›IRS International Taxpayer Service: +1 267-941-1000 (IRS international contact; also summarised on IRS from abroad)
• ›SSA International Call Center: +1 855-522-6936 (SSA foreign directory). The Office of International Operations geographic line is +1 410-965-0160

Best calling windows

US Eastern is UTC-5 (winter) or UTC-4 (EDT). The UK is 5 hours ahead in winter and 4 hours ahead in summer.

Best window for US government and bank helplines: 09:00-11:00 US Eastern (shortest morning queues). That is 14:00-16:00 UK time in winter or 13:00-15:00 UK time in summer.

The IRS says its waits are longer on Mondays and Tuesdays and shorter Wednesday through Friday, and that they average about 8 minutes in the January-April filing season and about 15 minutes from May to December. Most other US institutions publish nothing, so this guide does not guess for them. The IRS international line runs from 06:00 ET, which is late morning UK time.

Pitfalls specific to this corridor

• ›Domestic 1-800 on benefit letters. SSA’s 1-800-772-1213 and IRS 1-800-829-1040 are the most common wasted UK→US dials. The letter rarely prints the international alternative next to the bold toll-free headline, dig for the “outside the United States” paragraph on the agency site before redialing.
• ›NANP confusion with Canada and the Caribbean. +1 also serves Canada and several Caribbean territories. Confirm the area code is US before assuming US rates, hours, and holiday closures.
• ›DTMF on tax and bank IVRs. US agency menus are deep; some softphone routes deliver touch-tones poorly. If the menu restarts after every keypress, switch route or device before investing in a long hold.
• ›Hold music drops on weak Wi-Fi. A 40-60 minute IRS hold fails if the laptop sleeps or the network roams between SSIDs. Plug in power, disable sleep, and prefer a wired or stable 5 GHz link for anything expected to exceed 15 minutes.
• ›US federal holidays vs UK bank holidays. The calendars do not match. A quiet UK Monday can still be a US holiday with skeleton staffing, check the US federal holiday list before committing an early morning to a queue.

Quick checklist

• ›Dial +1 plus ten digits; do not add a UK-style leading 0.
• ›Replace failed US toll-free numbers with the published international/geographic line.
• ›Aim for 09:00-11:00 US Eastern when possible.
• ›Have SSN/ITIN, account numbers, and notice IDs ready.
• ›Prefer a per-minute route unless a UK international pass already covers the US cheaply.