I can instruct employer to salary sacrifice $2000-$2500/week into super for those 17 weeks and worry about tax due at later stage when I do tax return.
No you cant. That would put your total annual concessional super contribution over $30K.
The $30K (for YE 2025) includes super guarantee, salary sacrifice, and any extra consessional super contribution)
If you go on LSL + annual leave holiday then your employer will put in super guarantee payment.
Your employer should put in 11.5% super guarantee - thats good because thats another year of being able to contribute up to $30K in concessional super. especially if the year before you maxed out the $30K concessional contribution limit.
This is what i would do:
Lets say your LSL + annual leave including leave loading = $50K
And lets say your income for 1Jul (when you go on holiday) to 30Jun at end of financial year is $50K
The tax in $50K= $5788
Add 2% medicare levy = $1000
total tax = $6788
Total tax % = 6788/50000 = 13.6%
This is under the 15% tax on concessional super contributions.
This means you should put in the entire amount of $50000-$6788 = $43212 as an After tax Non Concessional contribution because your tax rate is LESS than the 15% super tax. If you send a notice to claim a tax deduction to the super fund in order to put it in as a concessional contribution, you effectively get taxed higher for the part that is concessional contribution.
Now here is the interesting bit:
When would your total tax (not marginal tax) be 15% including medicare levy such that it is equivalent to super contribution tax?
When your taxable income is around $54500.
So if your taxable income while you are on LSL leave is > $55000, put as much as possible as a concessional contribution - do this as a notice of intention to claim a tax deduction and the rest of your contributions as non concessional.
As your employer pays 11.5% x $50000 = $5750, you can put in $24250 as concessional and the rest as non concessional.
Note that the $30K limit will change in future years
The other think I would do is see the financial adviser from your super fund***. Most super funds have this service - there may be a $charge.