Flexible working granted. Does employer need to change the contract?

[MintChocc]

I recently requested to work flexible hour and this was agreed to by my employer.

However, it was a verbal agreement.

Do they need to make me a new contract or can it just be agreed by a letter / email / verbally...?

I always found it was better to have it in writing just in case the managment changed

Thanks. What I meant to say is that if it is mandatory for them to make a new contract.

No. They need to confirm it in writing, but you don't need a whole new contract, a letter would be fine and would constitute a variation of your contract.

I changed my hours from FT to 30 hours a week last year and received an addendum to my contract. If you have it writing it makes it difficult for your employer to amend your new working hours should they wish to revoke them as it is part of your contract.

Yes they need to put it in writing:

www.gov.uk/flexible-working/after-the-application