unpaid nupaid upnaid punaid npuaid pnuaid unapid nuapid uanpid aunpid naupid anupid upanid puanid uapnid aupnid paunid apunid npauid pnauid napuid anpuid panuid apnuid unpiad nupiad upniad puniad npuiad pnuiad unipad nuipad uinpad iunpad niupad inupad upinad puinad uipnad iupnad piunad ipunad npiuad pniuad nipuad inpuad pinuad ipnuad unaipd nuaipd uanipd aunipd nauipd anuipd uniapd nuiapd uinapd iunapd niuapd inuapd uainpd auinpd uianpd iuanpd aiunpd iaunpd naiupd aniupd niaupd inaupd ainupd ianupd upaind puaind uapind aupind pauind apuind upiand puiand uipand iupand piuand ipuand uaipnd auipnd uiapnd iuapnd aiupnd iaupnd paiund apiund piaund ipaund aipund iapund npaiud pnaiud napiud anpiud paniud apniud npiaud pniaud nipaud inpaud pinaud ipnaud naipud anipud niapud inapud ainpud ianpud painud apinud pianud ipanud aipnud iapnud unpadi nupadi upnadi punadi npuadi pnuadi unapdi nuapdi uanpdi aunpdi naupdi anupdi upandi puandi uapndi aupndi paundi apundi npaudi pnaudi napudi anpudi panudi apnudi unpdai nupdai upndai pundai npudai pnudai undpai nudpai udnpai dunpai ndupai dnupai updnai pudnai udpnai dupnai pdunai dpunai npduai pnduai ndpuai dnpuai pdnuai dpnuai unadpi nuadpi uandpi aundpi naudpi anudpi undapi nudapi udnapi dunapi nduapi dnuapi uadnpi audnpi udanpi duanpi adunpi daunpi nadupi andupi ndaupi dnaupi adnupi danupi upadni puadni uapdni aupdni paudni apudni updani pudani udpani dupani pduani dpuani uadpni audpni udapni duapni adupni daupni paduni apduni pdauni dpauni adpuni dapuni npadui pnadui napdui anpdui pandui apndui npdaui pndaui ndpaui dnpaui pdnaui dpnaui nadpui andpui ndapui dnapui adnpui danpui padnui apdnui pdanui dpanui adpnui dapnui unpida nupida upnida punida npuida pnuida unipda nuipda uinpda iunpda niupda inupda upinda puinda uipnda iupnda piunda ipunda npiuda pniuda nipuda inpuda pinuda ipnuda unpdia nupdia upndia pundia npudia pnudia undpia nudpia udnpia dunpia ndupia dnupia updnia pudnia udpnia dupnia pdunia dpunia npduia pnduia ndpuia dnpuia pdnuia dpnuia unidpa nuidpa uindpa iundpa niudpa inudpa undipa nudipa udnipa dunipa nduipa dnuipa uidnpa iudnpa udinpa duinpa idunpa diunpa nidupa indupa ndiupa dniupa idnupa dinupa upidna puidna uipdna iupdna piudna ipudna updina pudina udpina dupina pduina dpuina uidpna iudpna udipna duipna idupna diupna piduna ipduna pdiuna dpiuna idpuna dipuna npidua pnidua nipdua inpdua pindua ipndua npdiua pndiua ndpiua dnpiua pdniua dpniua nidpua indpua ndipua dnipua idnpua dinpua pidnua ipdnua pdinua dpinua idpnua dipnua unaidp nuaidp uanidp aunidp nauidp anuidp uniadp nuiadp uinadp iunadp niuadp inuadp uaindp auindp uiandp iuandp aiundp iaundp naiudp aniudp niaudp inaudp ainudp ianudp unadip nuadip uandip aundip naudip anudip undaip nudaip udnaip dunaip nduaip dnuaip uadnip audnip udanip duanip adunip daunip naduip anduip ndauip dnauip adnuip danuip unidap nuidap uindap iundap niudap inudap undiap nudiap udniap duniap nduiap dnuiap uidnap iudnap udinap duinap idunap diunap niduap induap ndiuap dniuap idnuap dinuap uaidnp auidnp uiadnp iuadnp aiudnp iaudnp uadinp audinp udainp duainp aduinp dauinp uidanp iudanp udianp duianp iduanp diuanp aidunp iadunp adiunp daiunp idaunp diaunp naidup anidup niadup inadup aindup iandup nadiup andiup ndaiup dnaiup adniup daniup nidaup indaup ndiaup dniaup idnaup dinaup aidnup iadnup adinup dainup idanup dianup upaidn puaidn uapidn aupidn pauidn apuidn upiadn puiadn uipadn iupadn piuadn ipuadn uaipdn auipdn uiapdn iuapdn aiupdn iaupdn paiudn apiudn piaudn ipaudn aipudn iapudn upadin puadin uapdin aupdin paudin apudin updain pudain udpain dupain pduain dpuain uadpin audpin udapin duapin adupin daupin paduin apduin pdauin dpauin adpuin dapuin upidan puidan uipdan iupdan piudan ipudan updian pudian udpian dupian pduian dpuian uidpan iudpan udipan duipan idupan diupan piduan ipduan pdiuan dpiuan idpuan dipuan uaidpn auidpn uiadpn iuadpn aiudpn iaudpn uadipn audipn udaipn duaipn aduipn dauipn uidapn iudapn udiapn duiapn iduapn diuapn aidupn iadupn adiupn daiupn idaupn diaupn paidun apidun piadun ipadun aipdun iapdun padiun apdiun pdaiun dpaiun adpiun dapiun pidaun ipdaun pdiaun dpiaun idpaun dipaun aidpun iadpun adipun daipun idapun diapun npaidu pnaidu napidu anpidu panidu apnidu npiadu pniadu nipadu inpadu pinadu ipnadu naipdu anipdu niapdu inapdu ainpdu ianpdu paindu apindu piandu ipandu aipndu iapndu npadiu pnadiu napdiu anpdiu pandiu apndiu npdaiu pndaiu ndpaiu dnpaiu pdnaiu dpnaiu nadpiu andpiu ndapiu dnapiu adnpiu danpiu padniu apdniu pdaniu dpaniu adpniu dapniu npidau pnidau nipdau inpdau pindau ipndau npdiau pndiau ndpiau dnpiau pdniau dpniau nidpau indpau ndipau dnipau idnpau dinpau pidnau ipdnau pdinau dpinau idpnau dipnau naidpu anidpu niadpu inadpu aindpu iandpu nadipu andipu ndaipu dnaipu adnipu danipu nidapu indapu ndiapu dniapu idnapu dinapu aidnpu iadnpu adinpu dainpu idanpu dianpu paidnu apidnu piadnu ipadnu aipdnu iapdnu padinu apdinu pdainu dpainu adpinu dapinu pidanu ipdanu pdianu dpianu idpanu dipanu aidpnu iadpnu adipnu daipnu idapnu diapnu
Note: these 'words' (valid or invalid) are all the permutations of the word unpaid. These words are obtained by scrambling the letters in unpaid.