Sky to BT - MAC or Cancel+Fresh order ?

Some advice please. I don't know whether I should try and switch with a MAC code or whether I should cancel Sky, wait until my BB stops working (i.e. the line is clear) and then order fresh with BT. Obviously a MAC code has the least downtime, but a cancel + fresh install would avoid some of the horror stories.

I originally signed up to UKonline LLU a number of years ago. At that time I swapped from Zen and did indeed have to do a full cancel and clear the line as I was swapping to LLU. Needless to say it was a PITA. UKOnline got closed down in 2011 and I was switched to Sky the parent company. No problems there.
Throughout all this though I have always been on a BT line, I never switched to Sky line rental.
Now I'm looking to switch to BT but am concerned about how to do it. Especially as I have this legacy situation of originally being LLU, but I don't know if I still count as that, and not having Sky line rental, which is no longer an option for new customers.

Maybe this is all straightforward and simple with a MAC code (as I still have a BT line?) or maybe all the legacy will end up with confusion and double billing troubles.

Can anyone advise on the best course of action?

P.S. I'm looking to get the BT Totally Unlimited package, if that makes any difference.

Order a new line (which was free when I signed up earlier this year) and have Infinity on that. If you are happy with the new line\infinity get BT to move the old number to the new line and cancel - which again is what I did earlier this year.

As much as I'd love the speed increase I can't justify the extra £7 a month (£84 per year) for Unlimited BT Infinity 1.

I have just transferred using a MAC code and all went as sweet as pie with no horrors to report. I cancelled the DD after this month's payment went out and that's that.

Zen & UKOnline Both use SMPF Zen uses BTW and UKOnline used LLU Sky mainly is FMPF (Voice & BB LLU ) but still have legacy Easynet SMPF LLU kit at some exchanges , So although you have had xDSL service Via Partial LLU using a MAC code should not cause any issues, infact if you don't Migrate and cease the active xDSL (Sky SMPF LLU) they will possibly raise a cease charge as BT openreach will charge them,
My advice, if you want to switch ISP would be to use the MAC code and migrate to your chosen ISP ,
The line will be rejumpered onto the new isp's kit at the exchange just as a new line would, so i don't see that you have anything to gain by ordering a new line

Thanks. Sounds like trying to do it the MAC way is best then. And ring up Sky after the switch to make sure I'm not being billed anymore? Or just cancel the direct debit?

Not sure what Sky's T&C's are, Is it a case of the Mac acting as the notice period,or not, ? Most Isp's will continue to charge you upto the date you actually migrate, whilst some will charge for 30days ,

But once Sky have collected the Final payment, and all is correct then yes cancel the DD with your bank if you wish,

But depending on how sky operates and when you migrate during the final billing period could mean that you will in effect be paying 2 different isp's for a number of days or weeks, as there maybe an overlap after you new service is active ,

Trying to finesse the payment overlap to less than a week is not worth the hassle and could lead to trouble.