The most common pitfalls when signing documents digitally, and what you can do about them.

Introduction

Most signing processes go smoothly. When things go wrong, it’s almost always down to one of a few causes: the SMS TAN doesn’t reach the mobile phone, the link in the email is out of date, contact details are no longer correct, or a form hasn’t been saved. This article goes through these scenarios.

First, a few clarifications, as problems often lead to incorrect assumptions: a text message not arriving is rarely down to FP Sign. Usually, the number on file is out of date or the text message gets stuck between mobile network operators; both issues can be resolved by you.

An interrupted process is no cause for concern. You can reopen the link at any time and pick up where you left off. Signatures already provided by other parties involved will be retained.

SMS TAN not received

When you open the request, FP Sign displays the last four digits of the mobile number to which the TAN is sent. This is the first check: if the digits do not match your current number, the number is out of date.

Even if the number is correct, the text message may still not arrive. Text messages are occasionally delayed or not delivered at all between mobile network operators. In such cases, FP Sign offers the option of receiving a phone call instead.

1. Check the digits displayed

   FP Sign displays the last four digits of the number on file. If they match your mobile number, wait a moment and, if necessary, request the TAN again.

2. Have the TAN read out to you

   When you select ‘Receive TAN via phone call’, FP Sign calls the registered number and reads out the TAN. If the number is correct, this call will always go through, even if the text message was not delivered.

3. You can register a new number if the old one is incorrect

   Use the ‘Register new mobile number’ option to enter your current number. You’ll find this feature at the bottom right of the FP Sign login page or directly in the TAN entry dialogue box.

4. You confirm the change by email

   FP Sign will send an email containing a confirmation link to your address. The new number will only become active once you have clicked on the link. You should then reopen the request link and request the TAN.

Following a number change, the new number will be embedded in the signature. Please also notify us of the change so that we can update it in your master data; FP Sign does not automatically synchronise the number with us.

Link not working

There are three reasons why a link might not work. Either we have withdrawn the request and resent it, in which case only the most recent email is valid; or an expiry date set by us has passed; or the process has already been completed because you or a representative have already signed.

First, check whether there is a more recent email from FP Sign, including in your spam folder. If the link has expired or the process has been completed, FP Sign will display a corresponding message. In all other cases, we will resend the invitation; a quick phone call or email to us will suffice.

Email from FP Sign not received

FP Sign sends requests and finalised documents from its own sender addresses. Some email systems filter these as unknown. First, check your spam or junk folder and mark the sender as safe.

If you still haven’t received the email, the address we have on file may be out of date or contain a typo. Please contact us; we’ll check the address and resend the invitation. Changing the email address in an existing FP Sign account is handled via FP Sign’s support team, which we will arrange for you.

Rejecting a request

If the content is incorrect or something is missing, do not sign it; instead, reject it. In the action menu for the request, select ‘Reject’ and enter a brief reason. We will receive the feedback immediately and discuss the matter with you before sending a corrected document.

Rejecting a request is the intended way to raise queries. It is better than leaving the document open, as we would then not know whether it has been overlooked or whether there is an objection.

Forward a request (delegate)

If another person is to sign – for example, because authorisation to sign lies elsewhere – you can delegate the request. This requires that we have authorised delegation at the time of sending.

1. Select ‘Delegate’ or ‘Sign and delegate’

   With ‘Delegate’, you forward the request without adding your own signature. With ‘Sign and delegate’, you first add your signature and then forward it to another person.

2. Enter the recipient’s details

   the name, email address and mobile number of the person who is to sign. The mobile number is required for the SMS TAN.

3. Confirm the recipient and complete the process

   Clicking ‘Confirm recipient’ and ‘Confirm’ forwards the request. The person will receive a separate email from FP Sign; we will be notified of the delegation.

Delegation is only available for requests involving a single document. For document folders, or if the option is missing from the menu, please let us know; we will send the request directly to the correct person.

Form cannot be completed or entries are missing

For fillable PDFs, such as a SEPA mandate, the button is labelled ‘Fill in and sign PDF’ rather than just ‘Sign’. You can start editing by clicking the pen icon above the blue signature field.

Once you have completed the form, you must save your entries by clicking the green tick in the bottom right-hand corner. If you proceed directly to signing, you will sign the form with empty fields. In this case, please do not reject the request; instead, contact us and we will resend the form.

If the button for filling in the form is missing altogether, the PDF does not contain any form fields. In that case, the document is intended for signing only, and the details will be collected by other means.

When you should contact us

There are some things that only we or FP Sign support can do. These include resending an invitation, withdrawing and resending an incorrect request, and adding a mobile number to our master data.

Common sources of error

• If you have requested a TAN multiple times and entered the first one: only the most recently sent TAN is valid. If you receive several text messages, the most recent one applies.
• Link opened from a forwarded email: The link is linked to the original email address and mobile number. The TAN will be sent to the wrong person.
• Spam filter permanently blocks FP Sign: Any further requests and confirmation emails end up in spam. Adding FP Sign to your list of trusted senders resolves this permanently.
• Request left open instead of being rejected: We cannot tell whether there is an objection or whether the email was simply overlooked. Rejecting the request with a reason is the clearer approach.
• Form signed without saving: The fields remain blank. The document must be sent again.

Frequently asked questions

Legal notice

This post provides an overview and is not a substitute for individual advice. The range of functions, terminology and menu navigation in FP Sign may change as a result of updates.

If you have specific problems with a signature request you have received from us, please contact us directly.

Last updated: September 2026