How to set an event contingency allowance
Someone said to add ten per cent for surprises, and nobody can say what it is for.
The short answer
A contingency allowance is a separate, named reserve for costs you cannot yet price. Size it line by line according to how certain each cost is. Keep it apart from the base budget and release it only through a named approver.
A flat percentage on the whole budget is the weakest method. A signed quotation needs little reserve; an estimate or an unscoped item needs more.
What a contingency covers
- It is for uncertainty inside the agreed scope: a quotation not yet received, a supplier cost that may change or a quantity that may rise.
- It is not for new scope. A new session, a larger venue or an added reception goes back to the committee as a change request.
- Keep it visible as its own line so the base budget can be read honestly.
Size it by certainty, not by habit
Group your lines by how firm the number is, then let the committee choose a reserve percentage for each group.
| Certainty level | What it looks like | Reserve approach |
|---|---|---|
| Firm | Signed quotation or contract with stated inclusions. | Small or none. Check for items quoted separately. |
| Estimated | Verbal or indicative figure, or a past-event figure. | A higher percentage chosen by the committee. |
| Unscoped | Item not yet specified, for example a speaker travel plan. | A named allowance until the scope is written. |
| Named risk | A specific event you can describe, such as extra hours at the venue. | A fixed amount tied to the named risk. |
Keep the reserve out of the base budget
Show base cost, reserve and total on separate lines. If a supplier quotation already includes a contingency, do not add another on top. Note it and treat the line as firmer.
The contingency scenario calculator keeps base and reserve apart and shows the assumptions behind each scenario.
Decide who releases it and how
- Name the approver, usually the budget holder or treasurer, and the amount they can release without going back to the committee.
- Require a short note for each release saying what the cost is, why it was not in the base and which reserve it draws from.
- Report the remaining reserve at every committee update, together with what is still uncertain.
- Agree what happens to any unspent reserve before the event, so it is not spent just because it exists. See reserve release approval for the approval step.
Worked example · Fictional example
A reserve sized by line certainty
Fictional organisation and figures. The percentages are the fictional committee's own choices, not recommendations.
A fictional professional-learning team has a base budget of RM 100,000. RM 70,000 is covered by signed quotations and RM 30,000 is estimated. The committee chooses 2 per cent on the signed lines and 10 per cent on the estimated lines. It adds a RM 2,000 named allowance for venue overtime.
The reserve is RM 6,400, shown on its own line, and the total request is RM 106,400. The treasurer can release up to RM 1,000 alone; anything above goes to the chair.
| Group | Base amount | Reserve rule | Reserve |
|---|---|---|---|
| Signed quotations | RM 70,000 | 2 per cent | RM 1,400 |
| Estimated lines | RM 30,000 | 10 per cent | RM 3,000 |
| Named risk: venue overtime | RM 0 | Fixed amount | RM 2,000 |
| Total | RM 100,000 | RM 6,400 |
Use this yourself
Contingency allowance template
Copy this list into your budget file. Every item needs an owner and a date before the allowance is presented for approval.
- Base budget total (without reserve):
- Lines grouped as firm / estimated / unscoped, with amounts:
- Reserve rule chosen for each group and who chose it:
- Named risks and the fixed amount for each:
- Contingency already included inside supplier quotations (do not add twice):
- Total reserve and total request shown on separate lines:
- Release approver and the amount they can release alone:
- Required note for each release:
- Reporting date for remaining reserve:
- Treatment of unspent reserve:
Handle it in-house, or bring in help?
Your team can usually handle this when
- Most lines are covered by quotations and the committee agrees how to group the rest.
- A treasurer or budget holder is available to approve releases quickly.
- The event has run before and you have your own record of past overruns.
Outside planning help earns its fee when
- The event is new and many lines are unscoped, so the allowance is a guess without structured scoping first.
- Funders or members ask how the reserve was sized and the rationale needs to be documented.
- Several approvers disagree on what the reserve may cover and a neutral facilitator would move the decision along.
Need the reserve rules written into the plan?
If the reserve rules are unclear, an Event Blueprint can set out the budget with a visible reserve: lines grouped by certainty, named risks, the release route and the reporting rhythm. Your treasurer or finance contact decides the percentages, and the Blueprint makes the decision trail clear for the committee. Share your brief on WhatsApp and we will reply with which level of support fits and what it would cover.
Questions organisers ask
Is there a standard contingency percentage for events?
It depends on how certain your quotations are and how much scope is still open. The committee should choose and record its own percentage for each group of lines.
Should I tell suppliers about the contingency?
No. The reserve is an internal control. Suppliers should quote against a written scope, and any change to that scope goes through your approval route.
Can contingency cover a new session added late?
It should not. A new session is a change in scope. It needs a change request, an updated base budget and an approval, not a draw on the reserve.
Related resources
Content record: Written by the EventConsultant team to our editorial rules. Sources are listed on pages that rely on them.