Tip with change, having no time at all for port (7)
I believe the answer is:
ipswich
'all for port' is the definition.
The definition suggests a singular noun which matches the answer.
'tip with change having no time' is the wordplay.
'tip with' becomes 'ip' (I can't explain this - if you can you should believe this answer much more).
'change' becomes 'switch' (switching is a kind of changing).
'having no' indicates named letters should be taken away.
'time' becomes 't' (abbreviation).
'switch' with 't' removed is 'swich'.
'ip'+'swich'='IPSWICH'
'at' is the link.
Can you help me to learn more?
(Other definitions for ipswich that I've seen before include "Wolsey's birthplace" , "9 across town" , "County town of Suffolk" , "Country town of Suffolk" , "Suffolk town on the River Orwell" .)