You should be OK.
The MAC is valid for 30 days from issue, and has to submitted by the ISP to Openreach with the migration order within that time. As long as there is no error in the MAC, (very occasionally there is), Openreach accept it and then give the ISP the installation date. That date can be long after the 30 days is up.
I've never heard of a gaining ISP not submitting their order with it to Openreach on the day the customer orders from them.
The only thing that might go wrong is the MAC expires before you can order, maybe the day before, and you have to wait however long your old ISP takes to get a new one before you can carry on.
My broadband basic info/help site - www.robertos.me.uk
| Domains,website and mail hosting - Tsohost
Connection - Plusnet
Extra Fibre (FTTC). Sync ~ 53.5/15.2Mbps @ 600m. - BQM
"Where talent is a dwarf, self-esteem is a giant."
- Jean-Antoine Petit-Senn.
Allergy information: This post was manufactured in an environment where nuts are present. It may include traces of understatement, litotes and humour.
Edited by RobertoS (Tue 20-Nov-12 22:29:44)