Maternity pay advice please!

[Mylifesarainbow]

I left my teaching job last June to go on maternity. I let the school know that I would not be returning and the council also had it in writing. I forwent the 6 week half pay on the understanding that I didn't have to return and work it off.
Anyway, been offered a job as a HLTA and they would like me to start after February half term (this is ideal for me too). So do I just need to get in touch with the council and let them know so they can cancel my maternity pay early?