Senior Project Manager

Lead complex, high‑impact programmes that transform how organisations pay and support their people

We are looking for an experienced Senior Project Manager to lead complex, multi‑workstream implementation programmes for some of our largest and most strategic customers. This is a senior delivery role with real ownership, visibility and influence, accountable not only for successful project outcomes, but for strong customer relationships, commercial performance and continuous improvement across our delivery approach.

You’ll work closely with customers, senior internal stakeholders and cross‑functional delivery teams to ensure projects are delivered on time, to the highest quality standards and within agreed budgets, often across programmes valued at £300k+ and employee populations exceeding 10,000.

You'll be based remotely and will enjoy working from home but will also be flexible to visit both Zellis and customer offices as required (approximately 3-5 times per month, with occasional overnight stays).

What you’ll be doing

In this role, you will:

• Lead end‑to‑end delivery of complex implementation and change programmes, often involving multiple workstreams and stakeholders
• Own the customer relationship throughout delivery, working in true partnership with customer Project and Test Managers to create a “one team” approach
• Develop and maintain robust project plans, aligned to the Zellis implementation methodology, including milestones, dependencies and entry/exit criteria
• Manage delivery performance, including KPIs, risks, issues, governance, budgets, commercial margin and P&L
• Provide clear, confident reporting to customers and senior Zellis stakeholders, including steering groups and executive‑level forums
• Lead and support delivery resources, acting as a point of escalation and ensuring teams are set up for success across each project phase

At Zellis we create market-leading HR & Payroll products and services, to power exceptional employee experiences so that you and your people do better. Our multi-award-winning products pay over five million employees a year, with almost half (42%) of the FTSE 100, 50% of the top retailers and 30% of the top universities in the UK & Ireland as customers, making us the largest provider of Payroll and HR software and managed services.

Our vision is to be the clear leader in pay, reward, analytics, and people experiences. We're passionate about creating an environment where people want to join, belong to, and be part of a progressive organisation. Our values, which were defined with input from all of our 2,000 colleagues, we live and breathe every day:

• Unstoppable together.
• Always learning.
• Make it count.
• Think scale.

Our people are critical to our ongoing success; we’re proud of our inclusive culture that gives you the platform to grow, challenge the status quo and play a crucial role in further enhancing our market position as the leading provider of HR & Payroll software and services. With Zellis you’ll have the chance to stretch and challenge yourself in an environment that’s varied, flexible and hugely supportive.

We also love to reward and recognise our brilliant colleagues. As part of your benefits package, you’ll receive:

• A competitive base salary, plus cash car allowance.
• 25 days annual leave, plus your birthday off and the opportunity to buy additional holiday.
• Private medical insurance.
• Life assurance 4x salary.
• Enhanced pension scheme with company contributions up to 8.5%.
• A huge range of additional flexible benefits across financial & personal wellbeing, lifestyle & leisure.