Number porting rejections

A porting request may be rejected for several reasons, here are some of the preventable reasons for rejection and the steps you can take to avoid them. Some of the more common reasons for rejections can be found below.

LCP Installation Postcode invalid (code 41) - the postcode submitted does not match the records of the current/losing provider.

This is one of the most common problems with porting, the end user must ensure the address they've provided matches what their current provider (CP) has on record. In particular, if the end user has moved premises since they first purchased the number.

Billing Telephone Number (BTN) mismatch (Code 30) - the main billing number (MBN) does not match the records of the current/losing provider.

This may happen simply if the number has been incorrectly added to the LOA. This must be checked with the end user.

Security lines associated with this number which have no order to cancel or transfer (Code 47) - there is a physical security line on the end user's installation that has no active order to either cancel or transfer it to another number or line.

If a physical security line is associated with one or more numbers on the port request, the order cannot be placed until a separate cancel or transfer order has been undertaken with the security line provider. A common case is BT Redcare.

Number not in service (Code 31) - the number that you are trying to port is currently not active.

Any numbers that you wish to port must be in service with the end user's current provider. This is the most simple terms, means that the number must be routed to a valid destination that will result in a ringing or answered call when it is dialled. If the number is not in service, it must be brought back into service before we can submit another port attempt.

Number(s) have been ported away from the range holder to another provider (Code 30) - the original range holder of the number has previously transferred the number to another provider.

In this case, we must determine who the other provider is, to be able to contact them as part of the process. This is referred to as a subsequent (SUP) port. The easiest way to obtain this information is to speak to the end user and ask them to contact their current provider to find out.

You can request that the end user asks for the current Communications Provider Identity (CUPID) code for the number. The CUPID is a 3 digit number that all communication providers obtain when they register with OFCOM.

There are missing associated numbers or direct dial inward (DDI) ranges (Code 44) - the number(s) on the request also have additional numbers that are associated with them that must be included in any future port requests.

This can happen if the end user only wants one or two numbers but they also have associated ranges that were allocated from their current provider. All numbers must be included in a future port request, but depending on the nature of these numbers, they may be ported, remain with the current provider, or be ceased.

This is a multi-line order, not a single line: (Code 25) - this happens if the number on the request was specified as a single line number, but there are multiple lines.

This might happen if there is a single number on the port request, but it has multiple physical lines (quite common with a traditional BT ISDN setup), or if there are simply multiple numbers on the port request.

A full list of rejection codes can be found in the OFFTA porting guide.

Fine-tune your preferences

There are a number of cookies we need to use in order for our website to work properly. These cannot be disabled.

However, you can disable non-essential cookies for the third-party services we use, to help us provide better customer support, measure the performance of this website and run more effective marketing campaigns.

We use Google Analytics to measure the performance of our website. We do not store any personal data and your IP address is anonymised.


We use a live chat service called Natterly so we can privide support to you where available. Various cookies are stored so chats remain active when you change page.


We use various tracking cookies to help us measure the performance of our marketing campaigns and show you content and promotions we think you’d be interested in.

Allow all
Update your preferences

Hello there!

This website uses cookies in order to provide you with the most relevant information. Please accept cookies for the best experience.

For more details see our Privacy Policy.

I’m OK with that
Cookie preferences