Your National Insurance claim was rejected. Now what?

A rejection letter from National Insurance is not the end of the matter. Most of what decides an appeal is in the letter itself, and appeals run on deadlines that start the day it arrives.

Read the reason, not just the verdict

The letter states which condition was not met, and that is what you are answering. A rejection for missing documents is a different problem from a rejection on medical grounds or on qualifying periods, and each needs different evidence. Find the specific clause cited and write it down. If the reason is unclear or generic, request the full decision and the file, because you are entitled to know the basis on which it was made.

Appeals run on deadlines

There is a limited window from the date of the decision, and it is short. Diarise it the day the letter arrives, before you start gathering anything. If the deadline is close and your evidence is not ready, submit within the window with what you have and add material afterwards rather than missing it. A late appeal usually needs a separate justification you would rather not have to make.

Build the file the reason asks for

Match your evidence to the stated ground. Medical rejections usually need up-to-date, specific opinions rather than the same records already reviewed. Employment or qualifying-period rejections need payslips and employer confirmations covering the exact months in dispute. Keep a copy of everything submitted and the date it went, and use a method that proves delivery.

FAQ

Can I appeal without a lawyer?
Yes, and many appeals are made without one. Getting the evidence right for the stated ground matters more than legal argument at this stage.
They rejected me for missing documents I sent.
Send them again with proof of the original submission — the date and method. This is one of the most straightforward rejections to overturn.
Should I just file a new claim instead?
Sometimes, but not always. A new claim can restart entitlement from a later date, so check which route protects the earlier date before choosing.
What if I miss the deadline?
There may still be a route, but it usually requires explaining the delay. Act as soon as you notice rather than waiting to prepare a perfect file.