If you see last few lines you ll see a lot of repeated name space declarations. Seems like a waste of space, anyway I can avoid it and have this name space towards the begining of the xml.
<ACAUIBusinessHeader xmlns="urn
gov:treasury:irs:msg:acauibusinessheader"><acabushdr:ACABusinessHeader wsu:Id="WSUID"
xmlns:acabushdr="urn
gov:treasury:irs:msg:acabusinessheader" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/ ... ty-1.0.xsd"><air7.0:UniqueTransmissionId xmlns:air7.0="urn
gov:treasury:irs:ext:aca:air:7.0">UniqueTransmissionId</air7.0:UniqueTransmissionId><irs:Timestamp xmlns:irs="urn
gov:treasury:irs:common">2015-11-05T14:43:30.00</irs:Timestamp></acabushdr:ACABusinessHeader>
<air7.0:ACATransmitterManifestReqDtl wsu:Id="EIN"
xmlns:air7.0="urn
gov:treasury:irs:ext:aca:air:7.0" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/ ... ty-1.0.xsd"><air7.0:PaymentYr>2015-11-05T14:43:30.00</air7.0:PaymentYr>
<air7.0:PriorYearDataInd>PriorYearDataInd</air7.0:PriorYearDataInd>
<irs:EIN xmlns:irs="urn
gov:treasury:irs:common">EIN</irs:EIN><air7.0:TransmissionTypeCd>TransmissionTypeCd</air7.0:TransmissionTypeCd>
<air7.0:TestFileCd>TestFileCd</air7.0:TestFileCd>
<air7.0:OriginalReceiptId>OriginalReceiptId</air7.0:OriginalReceiptId>
<air7.0:TransmitterForeignEntityInd>TransmitterForeignEntityInd</air7.0:TransmitterForeignEntityInd>
<air7.0:TransmitterNameGrp>
<air7.0:BusinessNameLine1Txt>BusinessNameLine1Txt</air7.0:BusinessNameLine1Txt>
<air7.0:BusinessNameLine2Txt>BusinessNameLine2Txt</air7.0:BusinessNameLine2Txt>
</air7.0:TransmitterNameGrp>
<air7.0:CompanyInformationGrp>
<air7.0:CompanyNm>CompanyNm</air7.0:CompanyNm>
<air7.0:MailingAddressGrp>
<air7.0:ForeignAddressGrp>
<air7.0:AddressLine1Txt>AddressLine1Txt</air7.0:AddressLine1Txt>
<air7.0:AddressLine2Txt>AddressLine2Txt</air7.0:AddressLine2Txt>
<irs:CityNm xmlns:irs="urn
gov:treasury:irs:common">CityNm</irs:CityNm><irs:ForeignProvinceNm xmlns:irs="urn
gov:treasury:irs:common">ForeignProvinceNm</irs:ForeignProvinceNm><irs:ForeignPostalCd xmlns:irs="urn
gov:treasury:irs:common">ForeignPostalCd</irs:ForeignPostalCd></air7.0:ForeignAddressGrp>