Pension letter

Hi
Each year DWP send me a form to put my increased pension amount on and send them a copy.
They sent me the form this year but my ex employer hadnt sent the pension letters, so in the meantime i lost the DWP's pension form.
I rang them and they gave me an address to send the pension letter to but the address seems vague and I am wondering if someone can reassure me that the form will get to them.
The address they gave me is "freepost dwp esa 25" no post code
How can I be sure that my pension letter will get to such a short address?
Thanks

Gordon wrote: Chrissy

The DWP use these addresses a lot the only issue is that you cannot use a Tracked post as there is no postcode.

Gordon

Thank you Gordon