Index
Preliminary information
Most likely, the first question that came to your mind regarding the digital signature is whether a signature placed via the touch-screen of a smartphone has equal legal validity of a "traditional" signature with pen. Well, in a nutshell, the answer is that yes, the signature made on the touch-screen has the same value as the one made with a pen on paper. To change is only the means by which it is affixed.
More specifically, I think it is better to make some clarifications. There signature autograph with smartphone it is completely similar to that with paper and pen even in the case of a dispute, where the veracity of the appropriate signature is in any case subject to evaluation by a judge. The only difference therefore lies in the digitization of the signature at the time of its affixing, nothing different (from the point of view of its validity) than the signature affixed with a pen which is then digitized by scanning the entire document.
Having said that, it can also be useful to know the distinction of this type of signature signature (which is what I am talking about in this article), with other types of electronic signature, the legal validity of which is of varying degrees.
- Advanced electronic signature - it is a more secure version of the simple electronic signature which involves the use of signature means over which the signatory has exclusive control, thus allowing the integrity and originality of the signed document to be demonstrated. As for the simple one, this type of signature also has legal value, except in the case of signing contracts for real estate.
- Qualified electronic signature - this type of signature is created by special means, real "signature kits" sold by qualified companies (for example Poste cittàne and Aruba), which guarantee the integrity and originality of the signed document. Clearly, this type of signature has legal value and covers a wider range of contracts than simple and advanced electronic signatures.
- Digital electronic signature - it is an advanced electronic signature based on the application of a mathematical method that guarantees the asymmetric encryption of the signature. In other words, it is based on the use of two encrypted keys, one public and one private, which are used by the sender and the recipient to verify the integrity and originality of the signed document. This type of signature has legal value.
Given these differences, it is possible to conclude that the legal validity of the simple electronic signatures, with the exception of contracts for real estate, it is allowed as writing between private individuals: in the event of a dispute it is a judge who assesses its reliability and originality (as is already the case with pen and paper signatures).
How to sign a PDF from your mobile
Having made the necessary premises on the validity of a signature affixed via smartphone or tablet, I think the time has come to go into detail and talk to you about the various solutions for digitally signing documents. Here, then, how to sign a PDF from android e how to sign a PDF from iPhone with some of the best solutions available.
Adobe Fill & Sign (Android/iOS)
The first app I recommend you for sign a PDF from your mobile è Adobe Fill & Sign, produced by Adobe, the company that created this file format. The app is available at no cost both on Android (even on alternative stores, for devices that do not have Google services) and on the iPhone. To install it, after opening the address I just provided you with from your phone, tap on the button Installa / Ottieni and, if necessary, verify your identity.
After installing and opening the app, press the button Continue present at the bottom and, on the next screen, tap the button [X] positioned in the upper right corner, in order to skip the registration phase. Next, you'll be shown the app's home screen, with recently opened files at the bottom and an icon in the center Select a form to sign.
By tapping on this last icon you can choose between three items: From file (From PDF file on Android, File Browser your iOS), From gallery e Take. In addition, if you are using the app on iPhone, you can also choose to import a PDF file from the web by entering a URL.
In the case of signatures on PDF files, the option to choose is the first (the others are for signing photos already taken or to be taken on the spot). Then press the button Allow to access the navigation menu of the files stored in your smartphone.
After importing the PDF document to be signed, with a tap on its preview, press the icon again in the shape of fountain pen and press the button Create initials / Create signature. You will be asked to enter your digital signature via the touch-screen and to press on confirmation button placed at the top, once drawn on the screen.
On iOS devices, you can also take a photo of your signature after pressing the icon with a camera, or the one it depicts image, to upload your signature from an already taken photo.
Now you can tap the icon again fountain pen, to find your signature among the selectable options. Then, tap on it to see it transferred to the document and move it, if necessary, with a long tap where it needs to be placed. Then press the icon of blue arrow to zoom in or out, while clicking on the image of the basket to delete it from the document. When you have placed the signature in the desired point, tap on another point anywhere on the sheet to confirm.
To save the signed PDF document and send / save it, tap on the icon sharing located at the top, then choose how to share the PDF document. Alternatively, on Android, you can press the key back arrow, while on iOS you can tap the button end.
Adobe Acrobat Reader (Android/iOS)
The app I am talking about now is always signed by Adobe and distributed at no cost both on Android (even on alternative stores, for devices that do not have Google services) and on the iPhone. The main difference with the app I have already told you about, lies in the possibility of adding your own signature from image file also in the Android version.
To use Adobe Acrobat Reader, which is the mobile transposition of the famous PDF reader also available on PC, the first step to take is always to download the app and install it from the respective store. Next, open the latter and open the PDF of your interest, by tapping on the sheet and then on the voice On this device.
Now browse the documents in the tab Locations and, once you have found the PDF to sign, tap on it. Alternatively, if you can't find the file, tap on the tab Recent and press the key that looks like a folder (this will open the folder navigation menu of your smartphone).
You can also import a PDF file from the Adobe cloud service accessible via Adobe ID; in that case, tap on the tab Document Cloud to browse saved files online. When you have imported your PDF to sign in the app, continue by tapping the button in the shape of pencil, located in the lower right corner. Then select the item Fill & Sign from which you can also insert a signature by pressing the icon of fountain pen.
Now, tap on the option Create the company and select, from the top menu, how you want to import the signature. As I anticipated, in addition to tracing it with your finger, you can also insert a signature using the tool camera, or image. The difference in use lies in the simple fact that the first is used to frame a signature via the smartphone camera and then import it into the PDF, while the second is used to import a signature from a photo already taken.
Acquired the signature, press the button end, so as to preview the signed document, then confirm everything with a second tap on the button end. Depending on the version, Android or iOS, the moment in which the app asks you to place the signature can change, for example on iOS you have to place it before confirming the preview. For the rest, the differences between the two versions are minimal.
PDF Extra (Android/iOS)
The app PDF Extra is available both on Android (also on alternative stores, for devices that do not have Google services) and on iPhone. Its free version allows you to sign PDF documents in a very simple way.
After downloading the application and opening it, press the red button Get Started and tap the button [X] placed in the upper left corner. Then, tap the button again Close to find you in front of the main menu, where you can choose the option Fill & Sign.
Now press the button Allow to give the app permissions to access your documents, then use the navigation menu to find PDF documents stored on your phone. Then wait for the PDF to open and press the button [X], if the advertising message relating to the activation of the Premium version appears, close it with a tap on the button [X] (The paid Premium version includes some extra features, but it is not needed to sign documents).
From the icons located at the top, select the first one, QUICK SIGN, then tap on the item Add signature/initials to open the signature entry screen.
Now you can sign in this new screen and press the button OK placed at the top. Then, move your signature to the place in the document where you want to place it and choose the size, with a long tap.
Once this is done, you just have to save your signed document by pressing the button SAVE ASat the top right, and then type the file name and press the button SAVE. Be careful NOT to tap the button SAVE instead of "SAVE AS", otherwise you will overwrite the original file and you will not be able to go back.
### Other solutions to sign a PDF from mobile ###
The solutions seen so far do not fully satisfy you and are you looking for other tools to sign your PDF documents directly from your mobile? Don't worry, in this case you can consult this chapter with other equally valid solutions to be able to sign your documents from your mobile phone.
- DocuSign (Android/iOS/iPadOS) — l’app DocuSign is another free app that allows you to sign PDF documents. To be used it requires a registration. Following login (also possible via Google or Facebook account), it is possible to sign documents and propose to other people to sign one or more documents. To do this, select the document to be signed from the navigation menu and enter the signature, together with the name, title and date, then tap on SEND to send the signature request to your contacts. The app allows you to sign via touch-screen or via images already saved.
- Sejda (Online) - if you believe that the ideal solution for signing PDF documents from mobile is to not install any app but to use a web service via your favorite web browser, then I believe Sejda can be for you. After connecting to the service site, tap on the logo Upload a PDF file placed in the center, then select your PDF document to import it and once done tap on the logo with a stylized signature to select the option New signature. Proceed by choosing the option Draw, choose the color and trace the signature in the box below, finally save it by pressing the key SAVE. Conclude by placing your signature and tapping on the button Save changes, then make another one on the button Download.
- Jet Sign (Android / iOS / iPadOS) - this application is free and available upon registration. It requires an Internet connection to be used. After installing and opening it, proceed with the selection of the document by pressing the button My files, then press the button JUST ME, if you are the only one to sign, or OTHERS REMOTELY, to send a signing invitation to other people, or again OTHERS IN PERSON, if the people who need to sign are near you. The rest is child's play: press on the point where you want to insert the signature, tap on the button Add signature and trace the signature with your finger and then confirm the changes and save everything using the key Continue.
As you have noticed yourself, the solutions to sign a PDF from mobile are many and interesting. Using your smartphone to sign is certainly one of the most comfortable methods, however, you may also need more general solutions to sign, perhaps even from a computer. If so, I think I can help by recommending you to read my article on how to sign a PDF document.
How to sign a PDF from your mobile
