Before you can enter the Gateway to using the Child Maintenance Service (CMS) you have to have a Unique Reference Identifier (URI).

There are several ways to obtain the URI

1. By calling the Options Service on 0800 988 0988. The Options Service will take basic details such as your name, national insurance number, telephone numbers and whether there you are experiencing domestic violence. They will then explain about the options for child support such as how to make a private agreement.

If you have already tried to get child support in the past, or have an agreement which has broken down or if you decide at any point during this conversation that you want to use the CMS tell them and they will issue the URI to you and will hand your call over to the CMS who will make then take further details from you for your application.

2. By contacting the Options Service on their website and having a live web chat with them. They will explain your options and can issue a URI if you want to use the CMS. This saves the bother of a long initial phone.

3. By emailing them via their website (you could either let them explain their service to you by email OR if you have already decided that you want to use the CMS Service, can say that you intend to use the CMS and they will issue you with a URI by email).

When you contact them by live chat or email, you could ask that they call you back but we are told that they are very busy taking incoming calls and that they cannot guarantee the time when any callback will take place.

Once a Unique Reference Identifier has been issued, you then have to call the CMS on either 0800 988 0988 or 0845 266 8792, tell them your URI and make the application over the phone as online applications are not possible.

If you have already tried to sort child support out in the past, or have an agreement which has broken down and know that you want to access the CMS, you can ask the Options Service for a URI without having them go through the full explanation of the options.

The up-front charge for an application to the CMS is £20. There are further charges imposed for collecting payments and for enforcement action.

There is a waiver of the £20 fee where domestic violence has occurred and for applicants who are under 18 years of age.