When and How to Move on from an Assignment – Knowing When to Leave as an Interim

Knowing when to leave an interim assignment is something many new interims don’t consider until the latter stages of a contract. However, it’s crucial to have a basis for this decision before even starting the assignment.

Understanding Why Organisations Hire Interims

To determine the right time to leave, it’s important to first understand why organisations hire interims. Typically, assignments fall into one of the following categories:

• Filling a permanent vacancy for a short period – Organisations leverage the interim market for its speed and flexibility compared to the permanent hiring process.
• Project-based work – Focuses on a specific, well-defined initiative where an interim is required for a set period to achieve a clear objective.
• Consultancy and advisory – These roles vary widely but typically do not exist within the permanent workforce structure. Instead, they provide flexible, auxiliary support while still working toward a defined outcome.

Now that we’ve outlined the key categories, it’s important to recognize that the right way to step away from an assignment will differ depending on the type of contract.

Filling a Permanent Vacancy for a Short Period

I’ll begin with this one as it is the most common type of interim contract and also the one with the most factors to consider when deciding the right time to leave.

Interims are often expected to contribute beyond what a permanent employee would, using their experience to drive improvements. While fulfilling this expectation, you should also consider your personal motivations and professional reputation.

Key Question to Ask Yourself

Have you exhausted your added value and fallen into only delivering business-as-usual requirements?

Your answer to this will help guide your decision. For example, if you are motivated by challenge, the excitement of a new role, and the ability to make a tangible impact, this question will indicate when it’s time to seek a new assignment.

However, if your motivations differ—such as prioritising job security—you should assess how ending your current assignment would align with your long-term goals.

Protecting Your Reputation

It is also important to mention, your reputation as an interim is critical to your ongoing success. When leaving an assignment, certain actions can negatively impact your professional standing, such as:

• Leaving the organisation without sufficient cover before a permanent hire is in place.
• Not fully delivering on agreed outcomes.
• Failing to provide added value during your time in the role.

To avoid reputational damage, maintain open communication with your line manager throughout the assignment. Set clear objectives at the start, schedule regular progress meetings, and be transparent about your job search to give your employer time to prepare for your departure.

Project and Consultancy Assignments

For project-based and consultancy assignments, the primary consideration is how far you have delivered on the agreed objectives or outcomes.

If you have completed all initial objectives, you should consider moving on unless there is an offer for redeployment or additional work that aligns with your motivations.

It’s also important to acknowledge that these assignments often last longer than initially planned. Be mindful of this from the outset to avoid leaving a client mid-project without adequate support.

Adapting to Unexpected Changes

For project assignments specifically, the reality of the role may differ from initial expectations. If obstacles prevent you from delivering the project as originally intended, consider whether you can adapt to overcome the challenges or whether it would be best to exit the assignment early.

How to Move On

Now that we’ve discussed how to determine the right time to leave, it’s equally important to ensure a smooth transition for your client.

Keep Communication Open and Honest

This has already been mentioned, but to reiterate—maintain an open line of communication with your line manager and be upfront about your commitment to the role from the outset.

For example, if your long-term goal is to secure a permanent position elsewhere and you’ve taken this interim role as a temporary stopgap, make sure your client is aware. This allows them to plan accordingly in case you need to leave earlier than expected.

Notice Period

A typical notice period for an interim assignment is between one week and one month, rarely longer. However, it’s not advisable to give only the bare minimum notice. Your formal notice period may not provide enough time for your client to prepare for your departure.

Instead, consider how long it will realistically take for them to transition smoothly and treat that as your de facto notice period.

Handover

This may go without saying, but ensure you work closely with your client to provide a thorough and detailed handover to relevant stakeholders. This helps retain organisational knowledge and ensures continuity after you leave.

Final Thoughts

Most people join the interim market because they seek a different way of working compared to permanent roles. As such, it’s important not to become an "honorary" permanent employee while on an interim contract.

To determine when it’s time to move on, consider:

• The value you’re providing.
• Your motivation for work.
• Your professional reputation.

Set yourself up for an easy exit from the very start, and when the time comes to leave, do so in the right way—ensuring your contract is deemed a success by your client.