Answer by Kirill Polishchuk for XSLT to change namespace prefix

Try this XSLT:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"><xsl:output omit-xml-declaration="yes" indent="yes"/><xsl:strip-space elements="*"/><xsl:template match="*"><xsl:element name="ns:{local-name()}" namespace="http://my.ns.uri"><xsl:apply-templates select="@* | node()"/></xsl:element></xsl:template><xsl:template match="text()"><xsl:element name="ns:{local-name(../../*)}" namespace="http://my.ns.uri"><xsl:value-of select="."/></xsl:element></xsl:template><xsl:template match="@*"><xsl:element name="ns:{local-name()}" namespace="http://my.ns.uri"><xsl:value-of select="."/></xsl:element></xsl:template></xsl:stylesheet>

Output:

<ns:GetInvoiceList xmlns:ns="http://my.ns.uri"><ns:Response><ns:Bill><ns:BillStatusCode><ns:typecode>1</ns:typecode><ns:BillStatusCode>type description</ns:BillStatusCode></ns:BillStatusCode><ns:EBillProcessStatusCode><ns:typecode>2</ns:typecode><ns:BillStatusCode>type description</ns:BillStatusCode></ns:EBillProcessStatusCode><ns:BillCycleCode><ns:typecode>1</ns:typecode><ns:BillStatusCode>type description</ns:BillStatusCode></ns:BillCycleCode><ns:BillActivityCode><ns:typecode>3</ns:typecode><ns:BillStatusCode>type description</ns:BillStatusCode></ns:BillActivityCode><ns:ToDate><ns:BillStatusCode>...</ns:BillStatusCode></ns:ToDate></ns:Bill></ns:Response></ns:GetInvoiceList>