Help with query to exclude invalid values

Question

creating a one time program. it needs to exclude bogus credit card numbers. all credit card numbers will be in varchar(20) fields.
1) cannot be null
2) cannot be empty
3) cannot be all zeros
4) must be >= 16 digits and < 19, after removing leading zeros
5) leading significant digit cannot be 9 or 8
Having trouble with #3.
IF OBJECT_ID('tempdb..#tt')IS NOT NULL
DROP TABLE #tt;
select * into #tt from
(select '09876543211234567' union all -- bad card number. not to start with significant 9 or 8
select '923523425' union all -- bad card number. not to start with significant 9 or 8 and < 16
select 'ab' union all -- bad
select null union all -- bad
select '' union all -- bad
select '000000000000000000' union all -- bad - numeric value cannot be 0
select '00543210987654321' union all -- bad < 16
select '109876543210987654321' union all -- bad > 19
select '06543210987654321' union all -- good
select '76543210987654321' -- good
) d (cccard)
select * from #tt
WHERE cccard IS NOT NULL and ltrim(rtrim(cccard)) <> '' and cccard not like '%[^0-9]%'
and len(substring(cccard, patindex('%[^0]%',cccard), len(cccard))) > 15
and len(substring(cccard, patindex('%[^0]%',cccard), len(cccard))) < 20
and left(substring(cccard, patindex('%[^0]%',cccard), len(cccard)), 1) not in ('9','8')

Answer 1

Try this
select * from #tt
WHERE cccard IS NOT NULL and ltrim(rtrim(cccard)) <> '' and cccard not like '%[^0-9]%'
and len(substring(cccard, patindex('%[^0]%',cccard), len(cccard))) > 15
and len(substring(cccard, patindex('%[^0]%',cccard), len(cccard))) < 20
and left(substring(cccard, patindex('%[^0]%',cccard), len(cccard)), 1) not in ('9','8')
and PATINDEX('%[^0 ]%',cccard)>0
--Prashanth