Step 1: phone for a paper version of the form (0800 121 4600). If you use a paper form, they will backdate the payments to the date you asked for the form. It will be date-stamped, and you will have a 6 week deadline to send it back. If you apply online, it will be backdated to the time you completed the form, and pressed ‘submit’. It can take time to compile evidence and consider the questions, in addition to being emotionally taxing, so it is worth asking for the paper form, in order to have the 6 weeks to complete the form.