How to Write a Backfill Justification When an Employee Leaves

A backfill justification explains why an empty role should be refilled as it stands, changed or not replaced. It answers five questions in half a page: what work is at risk, what the vacancy costs, whether the role should change, what it will cost to fill, and what happens if you wait. Give figures, options and a recommendation.

Why backfills need a justification

A leaver feels like an automatic replacement, but finance leaders and executives often treat each vacancy as a chance to ask whether the role is still needed in its current form. Budgets change, work shifts, and teams may be able to absorb tasks. An approver who gets a request that says only that someone left and we need a replacement has to guess at the value, and the safest guess is to wait. A clear justification saves time for everyone. It shows that you have thought about the work, not just the seat, and it gives the approver what they need to say yes quickly. This guide is about backfills specifically. For the approval workflow itself, such as who signs and how to avoid self-approval, see our guide on the job requisition approval process. The best time to start is the day you hear about the resignation, not the last day of notice. Use the notice period to talk to the leaver about what they actually do, what they wish they had help with, and which tasks nobody else knows. That conversation often reveals that the role is different from its job description, which is exactly the information an approver wants. Be careful to treat the leaver respectfully and to follow your organisation's rules about what is shared and with whom.

The five questions every approver asks

One: what work does this role do, and who does it now? Two: what happens if it is not done or is done by others, in terms the approver cares about, such as revenue, risk, service levels or deadlines? Three: is this still the right role, or has the work changed? Four: what will it cost to fill and to employ, and is it already in the budget? Five: how long can we wait, and what is the cost of waiting? Build the justification around these five, in this order. If you can answer them concisely and with evidence, most requests are approved without a long discussion. If you cannot answer one, find out before you submit.

Step 1: describe the work, not the job title

List the main outcomes the role delivers in three to five lines. For example: closes the month-end accounts within five working days, handles the first line of customer queries for two product lines, manages three vendor contracts. Say which are done by the leaver alone and which are shared. Then say who is covering now and for how long that is sustainable. This shifts the conversation from a person to a set of tasks and makes the risk of leaving it unfilled visible. Get the facts from the manager, not from memory, and ask for an exit conversation or handover notes to confirm what the leaver actually did.

Step 2: show the cost of leaving it empty

Link the vacancy to something the approver recognises. Missed deadlines, overtime paid to cover, delayed projects, customers waiting longer, a risk of losing other staff because of overload, or compliance tasks not done. Use your own figures where you have them. If you do not have exact numbers, give clearly labelled estimates and say how you made them. An example only: if a vacancy leaves 20 hours a week of work with the remaining team and overtime is paid at 30 per hour, the cover costs about 600 a week, which should be compared with the cost of hiring. Do not invent figures to look precise. A modest honest estimate is more persuasive than a big unsupported one. Where you cannot put a figure on it, describe the risk in words and rank it. For instance: high risk, because the role holds the only knowledge of a compliance filing due in six weeks; medium risk, because customers wait longer; low risk, because the tasks can be paused for a month. Approvers prefer an honest ranking to a precise number you cannot defend. Mention what is already being done to reduce the risk, such as cross-training, so the approver sees you are managing it, not just asking for money.

Step 3: ask whether the role should change

A departure is the cheapest moment to change a role. Ask: has the work shifted? Are there tasks that can be automated, combined or moved? Does the team need a different skill, level or location? Could the role be part-time, flexible, junior with training, or contract for a while? Present two or three options to the approver rather than a single request: replace as is, replace with changes, or do not replace and redistribute with a stated impact. Recommend one. Approvers respond well to a thoughtful alternative because it shows you are managing the cost, not just filling a seat. Changing a role may affect pay, grade and contracts, so involve HR early and check local rules on changing terms. Think about three common patterns. First, the role has grown beyond its grade and the leaver was underpaid for it, so the replacement will cost more; say so and explain. Second, the role has shrunk because a tool or process changed, so part of it can be merged into another job. Third, the work needs a different skill mix, such as more data analysis and less administration. Each is a good reason to adjust the role, and each is easier to argue with a short description of how the work looks today compared with when the role was created.

Step 4: state the cost and the budget

Give the expected total cost: salary range, employer taxes or contributions, benefits, and recruitment costs. Say whether the salary is already in the budget because it was held by the leaver, and whether there is any saving from the vacancy period. Show the pay range you will advertise and that it is consistent with similar roles inside the company. If the market has moved and the replacement will cost more than the leaver did, say so plainly, with the reason. Include a realistic time to fill, and the date you need the person in place. These pieces let finance check the numbers without asking. If the role was funded in the budget, show that the money exists and where it sits. If the salary savings during the vacancy are being used elsewhere, say so. Where a replacement would be more expensive, you can propose offsetting measures, such as a lower starting point in the range with a review after probation, a part-year budget impact, or a phased start. Be transparent about assumptions, and include a line on the cost of delay so the approver compares like with like. Keep numbers consistent with those finance already uses, and ask finance to check them before you submit.

Fill-in template

Role: [title], [team], reporting to [manager]. Leaver: [last day]. Reason for request: backfill. 1. Work at risk: [three to five outcomes, with who covers now]. 2. Impact of leaving it empty: [risk or cost, with figures and a note on how estimated]. 3. Options: A) replace as is, B) replace with changes [describe], C) do not replace and redistribute [describe impact]. 4. Recommendation: [option and why]. 5. Cost and budget: [salary range, extras, in budget or not, source of funds]. 6. Timeline: [needed by], [expected time to fill], [interim cover plan]. 7. Hiring manager: [name], Approver: [name], Date: [date]. Keep the document to one page and attach the job description if it has changed. After the template, add a one-line ask, for example: I am asking for approval to open the search at [range] by [date]. Include a space for the approver's decision and conditions. If your organisation has its own form, use its fields and attach your half page as supporting detail. The aim is the same: a clear decision, recorded in writing, so that recruiting can start on solid ground and nobody has to ask later who agreed to what.

A worked example

An invented case. A support team of six loses its senior agent who handled escalations. The manager writes: Work at risk: escalated tickets, about a quarter of the agent's time spent coaching new starters, and weekend rota cover. Impact: the remaining five are covering escalations, and an estimated 15 hours a week is paid overtime at 25 per hour, about 375 a week as an example estimate. Options: A) replace as is; B) replace with a team lead hybrid role at a slightly higher range, to reduce escalations through coaching; C) not replace, move escalations to the team lead, with a risk of slower responses. Recommendation: B. Cost: range within the existing budget for the leaver's role plus a small extra, to be confirmed by finance. Timeline: needed in eight weeks, interim cover through overtime for no more than four weeks. The finance lead approves B, with a review in six months. All figures here are illustrations. Note that option C was included even though the manager did not want it. Showing the real alternative, and its impact, makes the recommendation more credible, because the approver can see that the choice was considered. Also note that the interim cover has a limit. Approvers worry about open-ended temporary arrangements that become permanent and burn out the team, so stating an end date reassures them. Adapt the format to your own organisation and use real figures from your own records wherever you can.

Common mistakes

Asking for a replacement without describing the work. Using urgency instead of evidence. Giving only one option. Overstating the cost of the vacancy with unsupported figures. Forgetting to check the budget or grade. Making the change to the role without HR. Submitting too late, so the approval delays the search. Hiring before approval is complete. Not telling the approver about interim cover and its limits. Not following up: add a date in the diary to ask for a decision. Keep the document short, since long requests tend to wait. One more mistake is making the request about the leaver's value, which can sound sentimental, instead of about the work. Another is hiding a pay increase inside the request, which leads to a second round of questions. A third is assuming the answer will be yes, and starting the search before you have written approval, which can cause embarrassment and, in some organisations, breach policy. Finally, remember to update the approver if circumstances change, such as the leaver extending their notice or another resignation.

In Rezumz

In Rezumz, once a role is approved, the job workspace holds the job description and the must-haves for you to confirm, and CVs are ranked against them with the supporting evidence shown. Offers can be approved before they are sent, and notifications tell your team about changes. Rezumz does not write business cases or set headcount, so the justification itself is your work.