Standard AX doesn't give you much in terms of reporting around number seqeunces and their consumption. The query below will provide some basic info and can easily be modified to find number sequences that aren't set to preallocate. Using this every so often to maintain your sequences will prevent your users from seeing "Number sequence XXXX has been exceeded". DynamicsPerf also can give you some insight, if you have it configured.

select      'Number Sequence' = nst.numberSequence,
            'Name' = nst.txt,
            'Percentage Consumed' = (convert(real,(nst.NextRec-nst.Lowest))/(convert(real,nst.Highest-nst.Lowest)))*100,
            'Company' = isnull(nss.DataArea,''),
            'Party' = isnull(companyInfo.PartyNumber,''),
            'Operating Unit' = isnull(OMOperatingUnit.Name,''),*
FROM NumberSequenceTable nst
join NumberSequenceScope nss
  on nss.RecId = nst.NumberSequenceScope
and nss.partition = nst.partition
left join DirPartyTable CompanyInfo
  on CompanyInfo.RecId = nss.LEGALENTITY
and CompanyInfo.partition = nss.PARTITION
and CompanyInfo.InstanceRelationType = 41 -- TableId for extended table CompanyInfo
left join DirPartyTable OMOperatingUnit
  on OMOperatingUnit.RecId = nss.OperatingUnit 
 and OMOperatingUnit.partition = nss.partition
and OMOperatingUnit.InstanceRelationType = 2377 -- TableId for extended table OMOperatingUnit
 
WHERE ((convert(real,(nst.NextRec-nst.Lowest))/(convert(real,nst.Highest-nst.Lowest)))*100) > 70
  --AND nst.FETCHAHEAD = 0 --uncomment to find sequences that aren't preallocated