Digital And Hand Seal Information & Verification
Engineering Express utilizes multiple engineers in many states to provide both physical and digital certifications of our plans & calculations.
Understanding the requirements of professional engineer seals in each state will expedite code-compliant plans & permit processing.
Seal Example from Florida Guidelines
Understanding Physical (Printed) Seals
Most all states require original signatures and an embossed, ink (referred to as ‘wet’ seal) or CAD produced seals for physically printed engineering documents. Some states don’t permit all formats so it is encouraged to check with each governing board for proper seal format. Regardless of format, photocopies of plans should never be accepted as the primary engineering document due to risk of fraud, misuse, and liability. The National Society of Professional Engineers (NSPE) maintains a database of physical and digital seal guidelines by state found by clicking here.
Physical seals are fast being replaced by the more secure & efficient digital seal, especially after the COVID 19 outbreak.
Digital & Electronic Signatures

Digital Signature Authentication Example
There are two forms of digital signatures. One is an ‘electronic signature’ and one is a ‘digital signature’. An electronic signature is ‘self-signed’ through programs like adobe acrobat meaning you just ‘electronically sign the document’. The trouble with this is there is no way to verify that the electronic signature is truly yours. Therefore, states such as Florida (a leader in digital seal rules and the example set forth for other states) require the engineer electing to use the (free) electronic signature to prepare a hand signed & sealed ‘affidavit’ verifying the code (SHA-1) on the electronic signature truly belongs to them. For Florida, this is FAC rule 61G15-23.005.
Alternatively, the ‘digital seal’ method, FAC rule 61G15-23.004. This method utilizes a pay service to authenticate the signature via a secure cloud link to a pre-verified key. The reader of the document can click on the digital signature and see that it is in fact authentic.
The NCEES has written a helpful article on the topic which can be found here.
States in the US have adopted many variations of the electronic signature rule which are fast-evolving with the rush to digital work. the NCEES publishes a summary of state rules and where to find them. Contact them for an updated list. the 2018 list can be found here. The general theme throughout most all states in the US is
Documents digitally signed may be transmitted electronically as long as the signature is unique to and under the sole control of the person who applied it, be capable of verification and be linked to the document in such a manner that the signature is invalidated if any data on the document is altered
Other Helpful Information
Browse our knowledge base by clicking here to learn more about digitally & physically sealed plans.
Click to browse our article to learn how to validate a 3rd party digital seal by using Adobe or Bluebeam.
The signature of the principal engineer of the firm is frequently questioned. The registered signature of Frank Bennardo PE is a double left-handed swirl that appears in the image to the right.
If there are any questions as to the validity of a hand or digital signature please contact the office.
Last but not least, remember the rule:
Once digital, always digital. Once hard copy, always hard copy.
Translation: Digitally sealed plans can only exist in digital space.
Once a printed document is scanned, that’s not the originally sealed product.