    <SEC-DOCUMENT>0001308179-24-000396-index.html : 20240401
    <SEC-HEADER>0001308179-24-000396.hdr.sgml : 20240401
    <ACCEPTANCE-DATETIME>20240401120237
    ACCESSION NUMBER:		0001308179-24-000396
    CONFORMED SUBMISSION TYPE:	DEF 14A
    PUBLIC DOCUMENT COUNT:		72
    CONFORMED PERIOD OF REPORT:	20230515
    FILED AS OF DATE:		20240401
    DATE AS OF CHANGE:		20240401

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			CSG SYSTEMS INTERNATIONAL INC
    		CENTRAL INDEX KEY:			0001005757
    		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER PROCESSING & DATA PREPARATION [7374]
    		ORGANIZATION NAME:           	06 Technology
    		IRS NUMBER:				470783182
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		DEF 14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-27512
    		FILM NUMBER:		24807070

    	BUSINESS ADDRESS:
    		STREET 1:		169 INVERNESS DR W
    		STREET 2:		SUITE 300
    		CITY:			ENGLEWOOD
    		STATE:			CO
    		ZIP:			80112
    		BUSINESS PHONE:		3037962850

    	MAIL ADDRESS:
    		STREET 1:		169 INVERNESS DR W
    		STREET 2:		SUITE 300
    		CITY:			ENGLEWOOD
    		STATE:			CO
    		ZIP:			80112
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEF 14A
    <SEQUENCE>1
    <FILENAME>lcsgs2024_def14a.htm
    <DESCRIPTION>CSG SYSTEMS INTERNATIONAL INC - DEF 14A
    <TEXT>
    Document 1 - file: lcsgs2024_def14a.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>check01.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: check01.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>footer.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: footer.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>lcsg2024x1x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: lcsg2024x1x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>lcsg2024x3x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: lcsg2024x3x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>lcsg2024x40x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: lcsg2024x40x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>lcsg2024x40x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: lcsg2024x40x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>lcsg2024x40x3.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: lcsg2024x40x3.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>lcsg2024x40x4.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: lcsg2024x40x4.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>lcsg2024x40x5.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: lcsg2024x40x5.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>lcsg2024x42x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: lcsg2024x42x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>lcsg2024x43x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: lcsg2024x43x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>lcsg2024x43x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: lcsg2024x43x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>lcsg2024x4x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: lcsg2024x4x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>lcsg2024x5x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: lcsg2024x5x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>lcsg2024x5x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: lcsg2024x5x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>lcsg2024x5x3.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: lcsg2024x5x3.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>lcsg2024x5x4.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: lcsg2024x5x4.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>lcsg2024x5x5.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: lcsg2024x5x5.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>lcsg2024x6x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: lcsg2024x6x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>lcsgs003x46x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 21 - file: lcsgs003x46x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>lcsgs003x73x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 22 - file: lcsgs003x73x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>lcsgs003x79x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 23 - file: lcsgs003x79x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>lcsgs003x83x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 24 - file: lcsgs003x83x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>lcsgs003x84x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 25 - file: lcsgs003x84x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>26
    <FILENAME>lcsgsx11x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 26 - file: lcsgsx11x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>27
    <FILENAME>lcsgsx11x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 27 - file: lcsgsx11x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>28
    <FILENAME>lcsgsx20x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 28 - file: lcsgsx20x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>29
    <FILENAME>lcsgsx21x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 29 - file: lcsgsx21x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>30
    <FILENAME>lcsgsx25x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 30 - file: lcsgsx25x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>31
    <FILENAME>lcsgsx28x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 31 - file: lcsgsx28x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>32
    <FILENAME>lcsgsx29x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 32 - file: lcsgsx29x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>33
    <FILENAME>lcsgsx29x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 33 - file: lcsgsx29x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>34
    <FILENAME>lcsgsx30x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 34 - file: lcsgsx30x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>35
    <FILENAME>lcsgsx30x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 35 - file: lcsgsx30x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>36
    <FILENAME>lcsgsx31x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 36 - file: lcsgsx31x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>37
    <FILENAME>lcsgsx32x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 37 - file: lcsgsx32x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>38
    <FILENAME>lcsgsx32x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 38 - file: lcsgsx32x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>39
    <FILENAME>lcsgsx33x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 39 - file: lcsgsx33x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>40
    <FILENAME>lcsgsx33x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 40 - file: lcsgsx33x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>41
    <FILENAME>lcsgsx49x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 41 - file: lcsgsx49x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>42
    <FILENAME>lcsgsx49x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 42 - file: lcsgsx49x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>43
    <FILENAME>lcsgsx50x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 43 - file: lcsgsx50x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>44
    <FILENAME>lcsgsx50x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 44 - file: lcsgsx50x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>45
    <FILENAME>lcsgsx50x3.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 45 - file: lcsgsx50x3.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>46
    <FILENAME>lcsgsx70x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 46 - file: lcsgsx70x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>47
    <FILENAME>lcsgsx70x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 47 - file: lcsgsx70x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>48
    <FILENAME>lcsgsx71x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 48 - file: lcsgsx71x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>49
    <FILENAME>lcsgsx7x3.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 49 - file: lcsgsx7x3.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>50
    <FILENAME>lcsgsx7x4.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 50 - file: lcsgsx7x4.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>51
    <FILENAME>lcsgsx8x1a.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 51 - file: lcsgsx8x1a.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>52
    <FILENAME>lcsgsx9x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 52 - file: lcsgsx9x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>53
    <FILENAME>lcsgx13x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 53 - file: lcsgx13x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>54
    <FILENAME>lcsgx16x1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 54 - file: lcsgx16x1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>55
    <FILENAME>lcsgx16x2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 55 - file: lcsgx16x2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>56
    <FILENAME>logo.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 56 - file: logo.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>57
    <FILENAME>proxy1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 57 - file: proxy1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>58
    <FILENAME>proxy2.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 58 - file: proxy2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>59
    <FILENAME>uncheck.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 59 - file: uncheck.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>60
    <FILENAME>csgs-20231231.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION - SCHEMA
    <TEXT>
    Document 60 - file: csgs-20231231.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.DEF
    <SEQUENCE>61
    <FILENAME>csgs-20231231_def.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION - DEFINITION LINKBASE
    <TEXT>
    Document 61 - file: csgs-20231231_def.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>62
    <FILENAME>csgs-20231231_lab.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION - LABEL LINKBASE
    <TEXT>
    Document 62 - file: csgs-20231231_lab.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>63
    <FILENAME>csgs-20231231_pre.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION - PRESENTATION LINKBASE
    <TEXT>
    Document 63 - file: csgs-20231231_pre.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>65
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 65 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>66
    <FILENAME>R2.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 66 - file: R2.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>67
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 67 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>68
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 68 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>70
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 70 - file: FilingSummary.html

    Document 70 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>72
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 72 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>73
    <FILENAME>0001308179-24-000396-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 73 - file: 0001308179-24-000396-xbrl.zip

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>75
    <FILENAME>lcsgs2024_def14a_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 75 - file: lcsgs2024_def14a_htm.html

    Document 75 - RAW XML: lcsgs2024_def14a_htm.xml

    </DOCUMENT>
    </SEC-DOCUMENT>