How to fill open shifts without messaging every employee

The group message that says "can anyone work Saturday?" fills the shift eventually. It also reaches people who cannot do it, rewards whoever answers first and can land the shift on the person it costs the most or breaks a rule for. Here is how to offer an open shift to the right people, in the right order, and have it filled and recorded without the thread.

Written by Roster Flow. Published 15 July 2026.

An open shift is a shift on the roster with nobody in it. It might come from a sick call, a resignation, a busier week than expected or a swap that fell through. How you fill it matters more than it looks: the person who picks it up affects the wage bill, the breaks between shifts and whether the rest of the team thinks extra hours are shared fairly. A message to everyone solves the first problem, getting a name, and ignores the rest.

A smartphone lying in the dark with its lock screen lit up in blue, showing the time and date — Photo: Pexels

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Why messaging everyone backfires

It reaches people who cannot take it. Someone at university that day, someone already on long hours, someone who has never closed.
It rewards speed, not fit. The shift goes to whoever replies first, not the person best placed to do it or most in need of the hours.
It creates yeses you have to undo. Two people say yes, and one of them is told no after rearranging their day.
It skips the checks. Nobody looks at the break since that person’s last shift, or at whether their extra hours are paid as overtime.
It leaves no record. The agreement is buried in a thread, and the roster may never be updated.

Define the shift before you offer it

Write the shift down exactly before anyone hears about it. Vague offers get vague answers.

Date, start and finish. The actual times, not "Saturday morning".
Role and skills. Barista, kitchen hand or closing supervisor, and anything the person must be able to do alone.
Whether it can change shape. Could the shift start later or finish earlier, or be split between two people? Keep each piece above the minimum engagement in your award.
What it can cost. Decide in advance whether overtime or a more senior employee is acceptable for this shift, so you are not deciding under pressure when a name comes back.

Work out who is eligible

Before you offer the shift to anyone, filter the team down to the people who could take it without breaking a rule or the budget. The award rules in the table are from the Restaurant Industry Award 2020, the Hospitality Industry (General) Award 2020, the General Retail Industry Award 2020 and the Fast Food Industry Award 2020, as consolidated to 1 July 2026. Other awards set different rules, so confirm yours with the Fair Work Ombudsman’s Find my award tool.

The eligibility filter for an open shift
Check	What to look for	Where it comes from
Available	Their availability covers the shift. A part-time employee must not be rostered outside their written availability	Restaurant and Hospitality 10.7(a)
Has the skills	They can do everything the shift needs without help	Your own list of who can do what
Free at that time	Not already rostered, on leave or marked unavailable	The roster and leave records
Enough break	At least 10 hours between finishing ordinary hours one day and starting the next, or 8 at a changeover of rosters, for full-time and part-time employees	Restaurant 15.1(e); Hospitality 15.5(e)
Within daily limits	No more than 12 hours in a day or shift for a casual, and no more than 10 hours in a shift required of an employee under 18	Restaurant and Hospitality 11.2 and 13.3
Long enough	A casual is engaged and paid for at least 2 hours under the Restaurant and Hospitality awards, and 3 hours under the Fast Food award and generally under the Retail award; a part-time shift is at least 3 hours	Restaurant 11.3 and 10.7(b); Hospitality 11.3 and 15.2(a); Retail 11.2 and 10.9; Fast Food 11.3 and 10.2
The cost	Time beyond a part-time employee’s rostered hours is paid at the overtime rate, and a casual is paid a 25% loading	Restaurant and Hospitality 10.13(b)(iii) and 11.1

The people left after the filter are the short list, and only they hear about the shift. Keeping availability current is what makes the filter quick, and the availability and leave guide covers collecting it.

Offer it in a fair order

Decide the order once, write it down and tell the team, so nobody has to wonder why someone else got the extra hours. Common approaches are:

People who have asked for more hours first. Keep a list of who wants extra shifts, and offer to them before anyone else.
A rotating list. Each open shift starts one place further down the list than the last, so the same names are not always first.
Fewest hours this fortnight first. The eligible person with the lightest roster gets the first offer.
Cost first. A casual on ordinary rates before a part-time employee for whom the hours would be overtime.

Fairness has a legal side too. Under the Restaurant and Hospitality awards, a part-time employee who has regularly worked more ordinary hours than their guaranteed hours for at least 12 months can ask in writing for their guaranteed hours to be increased, and you can refuse only on reasonable business grounds, in writing (clauses 10.8 to 10.10). The General Retail award has a similar review (clause 10.11). For casuals, the National Employment Standards provide a pathway to permanent employment in some circumstances. A fair roster for casual employees goes further into sharing hours.

Send one clear offer with a deadline

Send the offer to the short list only, in one message with everything in it. For example:

Open shift: Thursday, 17:00 to 22:00, kitchen hand. Reply yes by 1pm today if you can take it. The first yes gets the shift, and no reply is fine.

A deadline stops the shift sitting in limbo, and saying how it will be decided stops arguments afterwards. If nobody on the short list says yes, widen the list one step at a time rather than jumping to everyone.

Sending an offer outside someone’s working hours is not unlawful, but employees have a right to disconnect: they can refuse to monitor, read or respond to contact outside their working hours unless the refusal is unreasonable. For small business employers, those with fewer than 15 employees, the right has applied since 26 August 2025. Writing the offer so that no reply simply means no respects that, and it keeps people willing to hear about the next one.

Confirm it and record it

Confirm to the personReply to the first eligible yes with the shift details, so they have it in writing.
Close the offerTell everyone else on the short list the shift is filled, straight away.
Update the rosterPut the shift on the roster and republish it, so the change is in the place everyone checks.
Record any part-time agreementUnder the General Retail award, a change to a part-time employee’s pattern by agreement must be recorded in writing, which can be a text message (clause 10.6). Under the Fast Food award, if there is no record of an agreed change to a shift, hours beyond the regular pattern are paid at overtime rates (clause 10.6).
Keep it with your recordsTime and wages records are kept for 7 years, so the offer, the acceptance and the roster change should be easy to find later.

A worked example: a Thursday dinner shift

A restaurant covered by the Restaurant Industry Award needs a kitchen hand for Thursday, 17:00 to 22:00, after a resignation. The manager defines the shift at 9:30 and runs the filter across the five kitchen hands.

Who is eligible for Thursday 17:00 to 22:00
Employee	What the checks found	Eligible?
Ali, casual	Available Thursday evenings and trained; rostered at 7:00 on Friday, 9 hours after this shift would end	Yes, with a question about the short turnaround
Bea, part-time	Written availability is Monday to Wednesday	No, clause 10.7(a)
Cal, part-time	Available Thursday evenings, but the 5 hours would be beyond his rostered hours	Yes, at the overtime rate under clause 10.13(b)(iii)
Dee, casual	Marked unavailable for the whole week	No
Eli, casual	Available, trained, no other shift that day, and has asked for more hours	Yes

The 10 hour break in clause 15.1(e) applies to employees other than casuals, so Ali’s 9 hour gap does not break the award, but a 22:00 finish before a 7:00 start is still worth raising with him. The restaurant’s written order is casuals who have asked for more hours first, then other eligible casuals, then part-time employees at overtime rates. At 10:00 the offer goes to Eli and Ali only, with replies by 13:00.

Eli says yes at 10:40. The manager confirms, tells Ali the shift is filled and republishes the roster. Eli’s 5 hours all fall between 6:00 am and 10:00 pm on a weekday, so under Table 8 in clause 24.2 they are paid at 125% of his minimum hourly rate, which includes the casual loading. Rates for each classification are on the Restaurant Industry Award pay rates page, and the roster cost calculator shows what the shift adds to the week.

A cafe worker in an apron wiping a table while holding a yellow cup and saucer — Photo: Pexels

Stop open shifts piling up

Some open shifts are unavoidable. Many are the same gap turning up every week, and those are cheaper to fix on the roster than to fill each time.

Look for repeats. If the same Thursday dinner is open most weeks, it belongs on the roster as a regular shift.
Track who picks shifts up. A simple count by person shows whether extra hours are going where your order says they should.
Publish earlier. Gaps found a week out are easier to fill than gaps found the night before, and how far in advance to publish a roster covers the timing.
Plan for sick calls. An open shift at 6:00 am needs a faster version of the same process, set out in what to do when an employee calls in sick.

Roster Flow keeps the pieces of this process together: availability and leave from staff phones, the roster published to everybody at once, clock ins that become timesheets, and approved hours sent to Xero, MYOB or a CSV file.

An open shift checklist

The shift is written down with its times, role and skills
Only eligible people hear about it, after the availability, break, limit and cost checks
The offer order is written down and known to the team
The offer has a reply deadline and says how the shift will be given out
No reply is treated as no
The shift is confirmed in writing, the others are told, and the roster is republished
Any change to a part-time employee’s hours is agreed and recorded in writing

Questions

Is it fair to give an open shift to whoever replies first?

It is quick, but it favours whoever happens to be on their phone. A written order, such as people who have asked for more hours first or a rotating list, is easier to explain and spreads extra hours more evenly.

What if a part-time employee keeps picking up extra shifts?

Under the Restaurant and Hospitality awards, if they have regularly worked more ordinary hours than their guaranteed hours for at least 12 months, they can ask in writing for their guaranteed hours to be increased. You can refuse only on reasonable business grounds, and must give the refusal and the grounds in writing.

How short can an open shift be?

It depends on who takes it. Casuals must be engaged and paid for at least 2 hours under the Restaurant and Hospitality awards and 3 hours under the Fast Food award and generally the General Retail award, and part-time shifts are at least 3 hours under all four.

Does the 10 hour break between shifts apply to casuals?

Not under the Restaurant Industry Award, where clause 15.1(e) applies to employees other than casuals, or the Hospitality award, where the rule sits in the roster clause for full-time and part-time employees (clause 15.5(e)). Other awards differ, so check yours.

What should an open shift offer say?

The day, start and finish times, the role, any skill it needs, the reply deadline and how the shift will be given out. Say that no reply is fine, so nobody feels pressed to answer on their day off.

Should I ask the whole team if nobody on the short list says yes?

Widen the list one step at a time instead, for example from casuals to part-time employees who want more hours, and run the same checks on each new name.

Sources

When an employee calls in sickThe first hour after a sick call.A fair roster for casualsSharing the shifts out evenly.Availability and leave guideKnow who can work before you offer.Roster cost calculatorWhat an extra shift adds to the week.

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