First, identify the real deadline
Write down the dismissal date or the date of the act you are complaining about. Then add the date you notified Acas and the date on the Acas certificate. The tribunal deadline can be affected by Acas early conciliation, so do not rely on a rough calendar guess.
Second, check the respondent
The respondent must be named correctly. Use the employer name on the contract, payslip, Companies House record, dismissal letter and Acas certificate. A mismatch can create problems, especially when time is already tight.
Third, protect the claim before polishing the story
A deadline week ET1 should be clear enough to show the legal claims and the key facts. It does not need to include every message, meeting or feeling. It should explain what happened, when it happened, who was involved, why it was unlawful and what remedy is sought.
Fourth, use headings by claim type
If you are claiming unfair dismissal, discrimination, unpaid wages, whistleblowing or victimisation, separate them under headings. This helps the tribunal understand the case and reduces the risk that an important claim is hidden inside a long narrative.
Fifth, keep preparation moving after filing
Filing the ET1 is not the end. After filing, you should organise evidence, preserve messages, prepare a chronology, note missing documents and start thinking about a schedule of loss. If the ET1 had to be filed quickly, later amendment or further particulars may be needed.