Key points
- The UK ETA form expects phone numbers in E.164 format: a plus sign, country code, and digits with no spaces or leading zeros.
- Most rejections come from wrong formatting, a mismatched country code, VOIP numbers, or browser auto-formatting.
- Retyping the number by hand, switching browsers, and disabling a VPN clears most entry and verification problems.
- You cannot change your phone number after you submit or once the ETA is approved, since it links to your passport.
- iVisa can pre-check formatting and handle the application on your behalf if SMS verification is a problem.
The UK ETA is a digital pre-travel authorization for visa-exempt visitors heading to the United Kingdom. It is quick to complete in most cases, but many applicants run into problems at one specific step: entering their phone number. The form expects an international format, and anything else tends to get rejected before you can move on.
This guide walks through why the phone number field fails, what the correct format looks like, and how to get past it so you can finish your application.
What is the UK ETA and who needs it?
The UK Electronic Travel Authorisation is required for travelers from visa-exempt countries who want to visit the United Kingdom for short stays. It is linked electronically to your passport rather than being a stamp or paper document.
During the application you are asked for contact details, including a phone number that can receive a verification message. That field is where a lot of applicants get stuck, because the system only accepts numbers written in a specific international format.
The correct phone number format
The UK ETA follows E.164 formatting rules. That means:
- A plus sign at the start
- Your country calling code
- The rest of the number, with no spaces, dashes, or leading zeros
Here is how a few common numbers convert:
| Country | As you’d write it locally | E.164 format |
|---|---|---|
| United Kingdom | 07700 900123 | +447700900123 |
| United States | (415) 555-2671 | +14155552671 |
| India | 09876 543210 | +919876543210 |
Notice that the leading zero drops off once the country code is added. That single detail is behind a large share of the errors people see.
Common issues and how to solve them
| Issue | What to do |
|---|---|
| Wrong format | Use E.164: plus sign, country code, then the number |
| Country mismatch | Select the correct country code for the number |
| Length errors | Remove extra digits or add any that are missing |
| VOIP number rejected | Use a real mobile SIM instead |
| Browser auto-formatting | Paste as plain text or retype the number |
| SMS not received | Check roaming settings and any SMS blocks |
| Too many code requests | Wait about 10 minutes before trying again |
Step-by-step fixes
If the field keeps rejecting your number, work through these in order:
- Confirm the country code and remove any leading zero from the local number.
- Retype the number by hand rather than pasting, so no hidden spaces or characters sneak in.
- Switch to a private browsing window, disable any VPN or ad blockers, and clear your cache.
- Try a different browser or device.
- Make sure you are using an SMS-capable SIM that can receive international messages.
How iVisa can help
iVisa is a private travel-document service, not the UK government, but it can smooth out the parts of the process that tend to trip people up. As part of preparing your application, iVisa:
- Pre-checks the formatting, adding the plus sign and removing leading zeros
- Validates the number’s length and characters before submission
- Can handle the verification step on your behalf
- Sends status updates by email so you can track progress
Note that iVisa charges a service fee for handling your application, which is separate from the UK government’s ETA fee.
Frequently asked questions
I can’t enter my phone number at all. What now?
Format it in E.164 style, type it manually instead of pasting, and remove any special characters. If it still fails, switch browsers, clear your cache, disable any VPN or ad blocker, and confirm your SMS settings work internationally.
Can I update my phone number after submitting?
No. You can’t change any details, including your phone number, after you submit the application or once it has been approved. The ETA links to your passport, not your phone number, so an out-of-date number does not affect your authorization.
What is the correct format?
E.164: a plus sign, your country code, and the number with no spaces or dashes.
Are non-UK numbers accepted?
Yes, as long as they can receive SMS. Avoid VOIP numbers, since verification systems may block them.
My verification code isn’t arriving. Why?
Confirm the number is in E.164 format, check that your carrier allows international SMS, and avoid sending repeated requests. Using a private browser window and turning off any VPN can also help.
Can iVisa help if I can’t access SMS?
Yes. iVisa can submit the application on your behalf without requiring device verification.
Related reading
- UK Government ETA app not working? A step-by-step guide
- UK ETA rejected? Get help to reapply quickly
- UK ETA scams: how to identify fake websites and apply safely
For the official requirements and to check your eligibility, refer to the UK government’s guidance on the Electronic Travel Authorisation.
