If I make a housing refund with cash to my CPF, is that amount tax deductible?

There is no tax relief with VHR (Voluntary Housing Refund). Remember you are refunding OA money you had withdrawn for housing, and you already enjoyed tax relief for those OA money when your employment contributions went into your CPF accounts.

No. But I still make voluntary housing refunds contributions anyway, because I want to hit my FRS asap.

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