Changing Envelope Size

[MTbowels]

I need to send some documents to a government department. They have provided a first-class reply envelope that will take A4 sheets folded in half (I think its called a C5 banker). I've tried to fold the documents in half but they simply won't fit in the envelope because there's so many of them.

Do you think I could glue the supplied envelope on a plain A4 sized envelope and send the stuff to them that way? Obtaining a second envelope from them is not an option, but I'm just wondering if the Royal Mail would accept and process an A4 envelope like I propose without me having to pay an additional fee.

Thank you

[MTbowels]

Should have said a first-class reply paid envelope. Sorry!

[Buenchico]

I've done exactly what you're proposing, with no problems whatsoever, on several occasions.

[MTbowels]

Thanks Chris. I'll do as you suggest.