Can another 2k be paid into the company pension and tax relief be claimed on it?
As far as my understanding goes (not a qualified financial adviser), based on the facts above:
The age-related % contribution limit for a 38-yr old is 20%.
The maximum contribution you can make to your company scheme is 20% of your €100,000 salary, so €20,000.
You are presently contributing 5% of your salary as payroll deductions, which is €5,000.
That leaves you room to contribute €15,000 as an AVC to your company scheme.
Assuming that the non-PAYE income of €10,000 is presumably Schedule D Case I/II (and not rental income etc.), you can contribute 20% of the €10,000 income (€2k), to a personal pension/PRSA, and avail of tax relief. You can't pay in an extra €2k into the company scheme and get tax relief as far as I know.
Example 3 on Page 11 of this link seems similar to your situation and is the back up for the above statements:
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