New VAT Number / Business Tax Account

Dear HMRC Team Member, We will appreciate if you can please help with the following queries: I had previously deregistered for VAT in 2019 and recently re-registered for VAT. The new VAT number has now been received. After reading some other posts in this forum I understand that the "Manage Account" option in BTA can be used to remove the old VAT Number. However, that has raised some questions as there are two options available under ' Manage Account' for removing the VAT number. Question 1. Which option should I be using (from (a) and (b) below) if the plan is to replace the old VAT number with the new VAT number in the CURRENT BTA? (a)Deregister a tax, duty or scheme from your account Explanation : You can stop submitting returns and making payments for any business taxes you have ceased trading for. (b) Deregister a tax, duty or scheme Explanation: Remove a tax, duty or scheme from your business account. You can remove tax information from this business tax account and add it to a different business tax account. Some of the other posts here have also suggested opening a new Business Tax Account (BTA) and attach the new VAT Number to it. I have been using my current BTA for last 8 years and also using it to file my corporation tax. The VAT returns associated with the old number are also in the current BTA. Question 2: If I open a new Business Tax Account, will I loose access to all my previous corporation tax returns for the last 8 years? or will all the returns associated with the business ( 8 years) be transferred to new BTA? Question 3: If the previous Corporation Tax returns wont be transferred to the new BTA, can I still maintain my access to the current BTA for record purposes? or does HMRC allow only one Business tax Account (per business) and upon activation of new BTA, it will terminate access to the old BTA? Question 4 : Is it essential that both the Corporation Tax and VAT are part of the same BTA? or can I leave the Corporation Tax in my current BTA, remove the old VAT number from it, open a new BTA and just attach the new VAT number to it ? Thank you in advance. Best Wishes, Commercial Specialist

Hi commercial Specialist,
I would recommend calling the VAT Helpline on 0300 200 3700 so that we can look at your account to determine the best option for you. 
Thank you.