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FAQ Mobile Phone Migration

On March 5, 2026, Nikhef will switch to a new mobile telephony provider. On this date, we will migrate from Vodafone to KPN. This change applies to all Nikhef users with a mobile phone number provided by Nikhef. Everyone affected has already received an email about this.

What does this mean for you?

  • You will keep your current mobile phone number
  • You will receive a new SIM card from KPN
  • By default, you will receive the same type of SIM card you are currently using:
  • physical SIM → physical SIM
  • eSIM → eSIM
  • There are, of course, no costs associated with this transition for you as a user

SIM cards: what will I receive and what do I need to do?

Physical SIM card

If you are currently using a physical SIM card, you will also receive a new physical SIM card from KPN.

  • Physical SIM cards can be collected at the Nikhef Helpdesk starting Monday, 23 February 2026.
  • The new SIM card will become active on 5 March 2026.
  • Approximately one hour before your number is ported, you will receive an SMS notification (the exact time may vary).
  • From that hour, you will no longer be reachable. This is the time to replace your SIM card.
  • After inserting and activating the new SIM card, you will be reachable again.

Important: Only replace your current SIM card on or after 5 March 2026.

eSIM

If you are currently using an eSIM, you will receive a new eSIM from KPN.

  • You will receive activation instructions in advance via your Nikhef email address.
  • Make sure you are connected to Wi-Fi, so you can access your email during the activation process.
  • The eSIM will become active on 5 March 2026.
  • Approximately one hour before your number is ported, you will receive an SMS notification (the exact time may vary).
  • From that hour, you will no longer be reachable. At that time, you can activate the new eSIM.
  • During activation, enter the confirmation code: 2026.

Prefer a different type of SIM card?

Would you prefer a different type of SIM card than the one you currently use (for example, switching from a physical SIM to an eSIM or vice versa)? That is possible.

  • Reply to the migration email that was sent or send an email to helpdesk@nikhef.nl by Thursday, January 29
  • Clearly indicate which type of SIM card you would like

Receive your SIM card by post

Unable to collect your physical SIM card at the helpdesk? We can send it to you in advance by post.

  • Reply to the migration email that was sent or send an email to helpdesk@nikhef.nl by Thursday, January 29
  • Include the full postal address where the SIM card should be sent, within the Netherlands or abroad

What will happen on March 5, 2026?

On 5 March 2026, your mobile subscription will be migrated from Vodafone to KPN.

  • Your phone number will be ported to KPN the day.
  • Approximately one hour before your number is ported, you will receive an SMS notification (the exact time may vary).
  • From that hour, you will no longer be reachable. This is the moment to replace your SIM card or activate your eSIM.
  • After replacing and activating your SIM card or eSIM, you will be reachable again.
  • Your phone may briefly lose network connectivity at some point during the day.

No connection?

If you have no connection to KPN after replacing the SIM card, first check the following:

  1. Is the new SIM card inserted or activated?
  2. Restart your phone
  3. Does the problem persist? Contact the helpdesk (visit us or attend the Office Hours on March 5 at 13:00)

Frequently Asked Questions (FAQ)

Will my phone work with KPN?

Most modern phones work seamlessly with the KPN network. Unsure? Please contact the helpdesk.

Do I need to adjust any settings?

In most cases, this is not necessary. For eSIM users, activation instructions will be sent to your Nikhef email address.

What if I am abroad on March 5, 2026?

That is not a problem. You can insert the physical SIM card into your phone on March 5. In the case of an eSIM, you will receive instructions via your Nikhef email address.

What happens if I collect my SIM card too late?

Your current SIM card will no longer work after the migration. Please contact the helpdesk as soon as possible.

Will my contacts, apps, or messages be affected?

No. The migration only concerns your mobile subscription. All data on your phone will remain intact.

Important: If you have stored contacts on your SIM card, these will not automatically be available on the new SIM card. Please check this in advance and transfer your contacts to your phone if necessary.

How do I check if my contacts are stored on the SIM card?

Android: Open the Contacts app → Settings → Manage contacts → Import/Export or SIM card contacts.
If you see “SIM contacts”, there may be contacts stored on your SIM.

iPhone: iPhones normally do not store contacts on the SIM card.
If you have ever used SIM contacts, you can check via Settings → Contacts → Import SIM Contacts (only visible if there is something to import).

Problems or questions?

Please contact the Nikhef helpdesk.

On March 5, CT Office Hours will also take place at 13:00. If you encounter any issues, feel free to stop by.