How do I get my Access Line ID

[Jacob31]

I'm switching provider from Sky and the new provider tells me we have two lines into the house which is news to me?  Despite my telling them the landline number we use they are asking for a ALID number, also known as the Line access ID/Number. Robot knows nothing and there's a 20 minute queue to speak to a human :0)

[JimM1]

@Jacob31 You will only be able to find that number and it is supplied by the ISP or if they know it already!