I froze DH's reports back in January. Any accounts that you have a current relationship with will still post to the reports. We just had Citgo pop up as a new account last month and some other accounts have had activity.
The thing that won't happen is that when you apply for credit - they won't be able to pull whichever report was frozen. A lot of people on this board and Credit Boards have Experian frozen because of issues with that agency.
Most times the company you apply for credit will tell you that they are unable to access your file and somethimes they will pull an alternative, or you can recon.
Also, a lot of people (on CB) have had better luck at credit repair on the Experian file by having the Experian froze. YMMV---------
Oh, I think that it took us 30 days for the Freeze to take effect.
10/01/2017 myFico EQ-778 TU-793 EX-781
11/01/2017 myFico EX-799, Barclays 11-4 Reported: EQ-796 TU-826 EX-799