TM Cloud Pre Search
A preliminary trademark search or knock out search is frequently used in an effort to avoid ordering expensive clearance searches when there are obvious impediments such as pre-existing registrations. A quick search of the trademark office databases in relevant jurisdictions may be enough to rule out a proposed mark.
The TMCloud Pre Search facility makes a preliminary trademark search across many jurisdictions easy. It can be accessed from the Dashboard or from individual trademark detail pages for many jurisdictions by using the Pre Search Local web link. It can also be used directly from the Practice Guide.
In addition to TESS and TSDR there are web links to many US States.
From Afghanistan to Zimbabwe: 129 national trademark databases
From Alabama to Wyoming: 40 US State trademark databases
Footnote: Keep in mind that pre-existing registrations need not always prevent your client from adopting a must have name. Registrations may be cancelled or acquired by assignment if the mark is not being used or is of no further interest to its owner.