Obtaining new EIN after changing status of DBA

I was doing business under a DBA, then I became incorporated.

When I incorporated, I applied for a new EIN - and got one. I have since closed that corporation and now again doing business as a DBA. But I did not get a new EIN this time.

Do I need a new one or can I use the EIN that was given to me the first time I had a DBA? (when I went as a corporation, I gave my previous EIN on the application)

You do not need a new EIN. You can use your first EIN, as long as you continue as a Sole Proprietor.

From the IRS website :

The IRS cannot cancel your EIN. However, if you receive an EIN but later determine you do not need the number (the new business never started up, for example), the IRS can close your business account. The EIN will still belong to the business entity and can be used at a later date, should the need arise.

Also, see Do You Need a New EIN? :

Generally, businesses need a new EIN when their ownership or structure has changed. Although changing the name of your business does not require you to obtain a new EIN, you may wish to visit the Business Name Change page to find out what actions are required if you change the name of your business.

Sole Proprietors You will be required to obtain a new EIN if any of the following statements are true.

• You are subject to a bankruptcy proceeding.
• You incorporate.
• You take in partners and operate as a partnership.
• You purchase or inherit an existing business that you operate as a sole proprietorship.

You will not be required to obtain a new EIN if any of the following statements are true.

• You change the name of your business.
• You change your location and/or add other locations.
• You operate multiple businesses.

I am a sole proprietor I will like to change to LLC. do I need a new Tax ID Number