Error with if statement

Anonymous 

Solved: DAX comparison operations do not support comparing... - Microsoft Power BI Community

You need to use double ampersand '&&' between your logical arguments. A single ampersand simply tries to concatenate text.

I'd also recommend using the SWITCH function in place of your nested IF statements as it makes the code easier to read.

Weekly Service Charge =
SWITCH (
    TRUE (),
    UnitCharge[ChargeFrequencyRef] = "M"
        && DATESBETWEEN ( UnitCharge[StartDate], 01 / 04 / 2018, 01 / 04 / 2019 )
        && UnitCharge[ChargeTypeId] = 2, UnitCharge[ChargeAmount] * 12 / 52,
    UnitCharge[ChargeFrequencyRef] = "Q"
        && DATESBETWEEN ( UnitCharge[StartDate], 01 / 04 / 2018, 01 / 04 / 2019 )
        && UnitCharge[ChargeTypeId] = 2, UnitCharge[ChargeAmount] * 4 / 52,
    UnitCharge[ChargeFrequencyRef] = "Y"
        && DATESBETWEEN ( UnitCharge[StartDate], 01 / 04 / 2018, 01 / 04 / 2019 )
        && UnitCharge[ChargeTypeId] = 2, UnitCharge[ChargeAmount] / 52,
    UnitCharge[ChargeFrequencyRef] = "W"
        && DATESBETWEEN ( UnitCharge[StartDate], 01 / 04 / 2018, 01 / 04 / 2019 )
        && UnitCharge[ChargeTypeId] = 2, UnitCharge[ChargeAmount]
)

Regards,
Ritesh
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