This is a two-part answer depending on the length of time you have been a non-member of the Federation:
If you have been out of the Federation for less than one year, you can apply through your DPF Branch Representative by completing the FIN 13
Forms. Your Branch Representative will send these forms to the appropriate Area Secretary, together with a signed declaration made by you, that you have no disciplinary matters outstanding, and that the Federation will not be held financially responsible for any matters that come to light during your period of absence from the Federation. The facts will be placed before the NEC for their approval. On acceptance, your application will be processed and your membership benefits will be reinstated.
If you have been out of the Federation for more than one year, the procedure is the same as above, except that financial penalties will be incurred in accordance with the DPF Rules & Constitution, which states: - RULE 3 (d) Any person making application for re-entry to the Federation and who has been a non member for more than one year, shall be required to repay six months subscriptions if re-entry is ratified by the National Executive Committee.