Articles on: Porting Phone Number

How to port UK’s Three phone numbers to KrispCall?

It is undeniable porting your UK’s Three phone number to KrispCall comes with enhanced benefits and is smooth.

Also, with KrispCall, business professionals, entrepreneurs, and individuals with specific needs can gain access to advanced call management features and seamless integration with many CRMs. All of that while keeping your current phone number through a streamlined porting process.

Using this guide, you will learn how to port UK’s Three phone numbers to KrispCall. Additionally, we will also learn about some other requirements that you will have to meet and provide before you can start and get going with the porting process.

Porting Requirements (To Be Considered Before Porting Out Your UK’s Three Phone Number)

Before initiating the porting process, there are a few things you need to consider. Here’s a detailed explanation of each requirement you need to consider before porting out your Three phone numbers to KrispCall:

1. The Number Must Be Portable

Firstly, you need to make sure that the number you are currently using is portable. Since not all phone numbers are eligible for porting, especially the ones used for specific services. So, it’s best to contact Three directly to confirm if your number can be ported before you start the porting process.

To check whether your phone number is eligible for porting. You can go to KrispCall’s Number Porting Eligibility Checker to quickly test and easily find that out.

2. The Number Must be Active

Next, you have to ensure that the Three phone number to be ported is active, in use, and in good standing at the time of porting to facilitate a smooth transfer process.

This means your account shouldn’t be suspended or disconnected due to non-payment or any other violation of Three’s terms. And if you intend to port your Three number, you should maintain your current service until the process has been completed.

3. The device Should Be Unlocked

Also, to port your number successfully, your device should be unlocked. If you’re using a phone locked to Three’s network, you’ll need to unlock it before porting your number, allowing it to be used with different network providers. That is because an unlocked phone can be used with any number from any compatible network provider.

If your device is locked to Three’s network, you can usually request an unlock code from them by reaching out to Three’s support.), although there might be a waiting period or fees involved.

4. Clear Outstanding Payments

Keep in mind, that you cannot port your number out to KrispCall if you have any outstanding charges on your Three account. Therefore, be sure that you’ve settled any and all remaining bills, including your final bill amount, any late fees, call charges, or charges for exceeding data limits before initiating the porting process. Once you clear all your dues, you can begin the porting process.

5. Submission of Necessary Documents & Information

Lastly, you will have to provide some documents and information to KrispCall to begin the porting process. The documents you need to provide are:

Letter of Authorization (LOA) issued within the last 30 days.
Customer Service Record (CSR).
Phone Bill.
6-digit Number Transfer PIN (Porting Authorisation Code, PAC).

Make sure all the information in these documents is accurate and up-to-date before submitting.

Information and Document Requirements (For UK Local, National & Toll-free Phone Numbers)

Here are the information and documents that you need to provide when porting your Three’s phone number to KrispCall:

1. Phone Numbers

This is the phone number (or list of numbers) you want to transfer from Three phone number to KrispCall. You’ll need to provide the phone numbers in their entirety, usually in the E164 format, which includes the country code (+44 for UK) followed by the area code (three to five digits) and the subscriber number(seven digits).

2. Letter of Authorization (LOA)

The next thing required is your LOA, which was dated no more than 30 days ago. Your Letter of Authorization validates your ownership of the number and provides everything needed to port and transfer the number successfully.

Here are some considerations that you need to look into in regard to LOA:

Letter of Authorization should be dated within the last 30 days. If you want to port both Geo and Non-Geo numbers, please fill in 2 separate LOAs – one for Geo and one for Non-Geo numbers.
LOA should be filled out digitally; only the signature can be done by hand.
Add the current provider as the “Current Retailer.” Note that you have to indicate a provider that is billing you for the service (it can be either a reseller or a network provider).
Leave the “New Provider” field blank.
Email contact of your current provider.
The site address must be in the United Kingdom.

LOA Template for UK’s Three Phone Number

3. Regulatory Compliance

Regulatory compliance refers to adhering to the rules and regulations set by government bodies (Ofcom) for the telecommunications industry in the UK.

RC approval is generally required for porting specific types of phone numbers, especially for those used for businesses with specific regulatory needs.

Here’s a table that outlines the information typically required for RC approval:

InformationDescriptionAdditional Comments
Account NameName associated with the phone number account.⚠️Incorrect information will lead to rejection
Account NumberUnique identifier for your phone service account.⚠️Incorrect information will lead to rejection
Company Name & Registration Number (if applicable)The registration number for your business and the name of your business if the phone number is associated with it.⚠️Missing any information will lead to rejection
Photo IDA copy of your government-issued photo identification (passport, driver’s license, etc.).⚠️Missing any information will lead to rejection
AddressA copy of your proof of address. (Government-issued ID showing your local address, Utility bill, Tax notice, etc.)⚠️Missing any information will lead to rejection

4. Most Recent Phone Bill

Before initiating the porting process, you must provide a digital or scanned copy of the most recent phone bill. It must include your address, authorized user name, and account number.

And make sure there are no outstanding payments or dues on your current Three account. Clear any outstanding bills to avoid any issues during the transfer.

5. Service Address

This is the location where you want your new phone service from KrispCall to be activated. This address can be anywhere in the world, regardless of your physical location.

Information and Document Requirements (For UK Mobile Phone Numbers)

Now, if you wish to port a UK mobile phone number provided by Three to KrispCall, you need to provide the following information and documents:

1. Phone Numbers

Here, you will need to provide information regarding your mobile number. Your mobile phone number is a unique identifier assigned to your SIM card or e-SIM by your mobile network operator (MNO) in the UK, here: Three.

Mobile phone numbers in the UK typically begin with “07” and are 11 digits long. In UK mobile numbers, the first three digits represent the network provider and the remaining digits are the subscriber number.

2. Regulatory Compliance

In the context of mobile phone number porting, these regulations are established by the Ofcom (Office of Communications). Here, RC also refers to following the rules and regulations set by the government or a governing body.

Following is a table outlining the information that is typically required for Regulatory Compliance (RC) approval during the porting & transfer of a mobile number:

InformationInstruction to FillAdditional Comments
Account Holder NameThe legal name of the person on whose behalf the mobile number is registered.⚠️Incorrect information will lead to rejection
Billing AddressA copy of your proof of address. (Government-issued ID showing your local address, Utility bill, Tax notice, etc.)⚠️Incorrect information will lead to rejection
Date of BirthThe account holder’s date of birth is for verification purposes.⚠️Missing any information will lead to rejection
The account holder’s date of birth is for verification purposes.The registration number for your business and the name of your business if the phone number is associated with it.⚠️Missing any information will lead to rejection
Photo IDA copy of your government-issued photo identification (passport, driver’s license, etc.).⚠️Missing any information will lead to rejection

3. Porting Authorization Code (PAC)

You also need to provide your PAC to KrispCall for the porting process. A Porting Authorization Code (PAC) is a unique code (often temporary) that will allow you to transfer your mobile number from Three to KrispCall while retaining the same number.

Your PAC will act as a verification tool for KrispCall to confirm your verification to port the number. You can obtain your PAC by simply requesting it from Three.

Also Check: How to port Telstra phone numbers to KrispCall?

4. Most Recent Phone Bill

Lastly, you also need to provide documentation regarding your phone bills.

You need to provide the most recent ones, as they will serve as proof of ownership and account details for the mobile number you’re trying to port. It usually contains information like your account holder’s name, billing address, phone number, and current service plan.

By meeting the above requirements, you can ensure a seamless and successful transfer of your Three mobile number to KrispCall while avoiding any potential complications during the porting process.

How to port UK’s Three phone numbers to KrispCall?

To port UK’s Three phone numbers to KrispCall, you can follow these simple steps:

Step 1: First, use our number Porting Eligibility Checker to determine whether your phone number can be ported or not. If you encounter any issues while using the tool, our team is available by live chat and email at or

Step 2: Send your request via live chat or email if the number is portable and you want to port it to KrispCall.

Step 3: Upon receiving your inquiry, a member of our support team will contact you and explain the required documents and information.

Step 4: Once you have been contacted, send your documents to Your mail should include all required documents and necessary information.

Step 5: The porting request will be approved by KrispCall if all of the documents provided are accurate and in the required format.

Step 6: Upon approval of the port request, our porting team will send it to the losing carrier (Three). After that, Three will send you an SMS text confirming your port approval. Approve it within 90 minutes of receiving it. Otherwise, your Port requests will be rejected if you fail to respond in a timely manner.

Step 7: Our support agent will begin the porting process as soon as you respond to the port approval SMS.

Note: You must keep your phone number active throughout the porting process.

Step 8: Once your porting has been successful, you will receive a notification and be able to access the number through KrispCall.

What rejections can cause porting delays?

1. Invalid/Incorrect Site Address

If the information you provide about your current carrier or account details is wrong, it will be rejected. This can cause delays as you’ll need to fix the information and resubmit the request. And it is one of the most common reasons behind porting delays.

2. Network Provider/Rh Blocking The Port

Another issue leading to delays is when the network provider or the Responsible Organization (RH) blocks the porting process. This can happen due to outstanding bills, contract violations, or even errors on their end. Delays occur while resolving the block.

3. Incorrect Line Type

If you provide the wrong information about the type of your phone number, it can cause a delay while you clarify the correct details. Remember different phone lines (landline and mobile) have different porting procedures and you need to ensure that the line type information matches accurately.

4. Incorrect Number Details

Wrong details about your phone number, account number, billing telephone number, or other identifying information can also lead to delays. To prevent delays, make sure all number-related pieces of information that you provide are accurate.

5. Inactive Number

If the phone number you’re trying to port is inactive or disconnected, the request will automatically be rejected. In order to port your number smoothly, you need to make sure that it’s an active number.

6. No Service With LCP

LCP (Local Carrier Provider) refers to your current service provider. And if they don’t offer porting services, your request will be rejected, and you won’t be able to port your number.

What are the common reasons for a rejected port?

Incorrect information about postcode.
Single- vs. multi-line geographic numbers: Associated numbers must be ported together as a range. To determine whether your number is a single- or multi-line number, reach out to Three.
Incorrect current provider and/or range holder information: Check with your current provider and the range holder of your phone number(s).


How do I transfer my UK’s Three phone number to another carrier?

In order to transfer your Three number to another provider, you need to call Three’s customer service department at +44 7782 333 500.

Then, follow these steps:

Send a porting request to your new carrier.
As required, submit accurate and current papers and information.
Be patient until your porting request is approved.
As soon as the new carrier accepts the request, it will inform you of the porting day and time.
Keep in touch with the new provider’s team to ensure that the porting process is going smoothly.

How can I get a UK’s Three phone number transfer PIN?

You can get your PAC (Port Authorization Code) from Three by calling 333 from your Three phone or 0333 338 1001 from any other phone.

How long does it take for UK’s Three to release your phone number?

Three will usually take a maximum of 2 working days to release your phone number.

Updated on: 05/04/2024

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