Regarding the rail fine, that is probably not a criminal record issue, as you violated the policy of a company rather than violating the law. If you hadn't paid the fine and they brought you to court it would have been different - are you sure it counted as a criminal conviction? This one is far enough in the past that it shouldn't be a worry, unless there is more detail that we should know?
Review the full good character requirement here
https://assets.publishing.service.gov.u ... racter.pdf
Fixed penalty notices, penalty charge notices and penalty
notices for disorder
Fixed penalty notices, penalty charge notices and penalty notices for disorder are
imposed by the police or other authorised enforcement officers for traffic rule
violations, environmental and civil violations. A fixed penalty notice may also be
issued where a person has committed an offence under the coronavirus Regulations.
It is a way of the criminal justice system disposing of minor offences without the need
for a person to attend court.
Receiving one does not form part of a person’s criminal record. A fixed penalty
notice will not normally result in refusal unless the person has failed to pay or has
unsuccessfully challenged the notice and there were subsequent criminal
proceedings resulting in a conviction. In such instances, they should be treated in
line with the sentence imposed by the court.
However, multiple fixed penalty notices over a short period of time, could
demonstrate a disregard for the law and therefore demonstrate that someone is not
of good character.
Considering the balance of probabilities
Where a person has criminality that would not normally result in the refusal of their
application, you must decide whether they are of good character, on the balance of
probabilities.
An assessment of whether or not a person is of good character on the balance of
probabilities, must take account of all available information concerning the
applicant’s character, weighing any negative factors around criminality against
mitigating factors such as contributions a person has made to society or any
significant proportions of a person’s life spent not offending.
You must consider the individual circumstances of the case; what may be
appropriate for one case will not be appropriate for another. Each application must
be carefully considered on an individual basis on its own merits, giving consideration
to the (non-exhaustive) list of factors below:
Length of time since offences
You must consider how long ago the offences took place. The more recent the
offence, the more likely it is the applicant is not of good character.
Older offences may still indicate the person is not of good character, if the
circumstances of the conviction or disposal call the person’s character into question.
It is also more likely that a person will not be meet the good character requirement on
the sole basis of non-custodial offences or out of court disposals where the offences
took place recently.
Number of offences
You must consider the number of offences on the applicant’s record. There is no set
number of non-custodial sentences or out of court disposals that would mean a
person is not of good character; however, the higher the number the more likely it is
the person is not of good character.
A person who persistently shows a lack of respect for, or desire to comply with, the
law of the UK, through frequent criminal activity and adverse engagement with the
judicial system, can be considered to show a particular disregard for the law.
Where a person is identified as a persistent offender who has shown a particular
disregard for the law, they will normally not be considered to be of good character on
that basis alone.
Period over which offences were committed
You must consider the period over which offences were committed or other
disposals occurred. For example, a series of minor offences or disposals in a short
space of time may indicate a pattern of sustained anti-social behaviour or disregard
for the law which will be relevant to the assessment of the person’s character.
Older non-custodial sentences or out of court disposals may be relevant if there are
other serious factors.
Where a person is identified as a persistent offender who has shown a particular
disregard for the law, they will normally not be considered to be of good character on
that basis alone.
The seriousness of the offence
The sentence or disposal should be the primary indicator of the seriousness of the
offence. You must consider the nature of any offence(s) the person has been
convicted of and whether they are offences which have caused serious harm. If the
offences are sufficiently serious it may be appropriate to refuse on the basis of
causing serious harm.
Any escalation in the seriousness of offences
You must consider if there is a pattern of offending. A person may have committed a
number of offences which have escalated in seriousness. For example, a person
may have been involved in theft which then escalates to burglary, and then
aggravated robbery. If the more recent offences are sufficiently serious it may be
appropriate to refuse on the basis of causing serious harm.
Nature of the offences
You must consider the nature of the offences or the behaviour that led to other
disposals. Anti-social behaviour, drug use, or violence may indicate that a person’s character is such that a refusal would be appropriate (particularly if there is a pattern
of such behaviour) on the basis of causing serious harm.
Applicant’s age at the date of conviction
You must consider the applicant’s age at the time non-custodial sentences were
imposed or out of court disposals took place. Isolated youthful indiscretions will not
generally indicate a person is of bad character if that individual has clearly been of
good character since that time.
Exceptional or other circumstances
You must consider the relevance of particular circumstances in a person’s life when
they committed the offence(s).
Other mitigating factors
You must also consider whether the applicant has demonstrated genuine,
meaningful attempts to change their behaviour and comply with the law that may
indicate, on a balance of probabilities, they are now considered to be of good
character despite earlier offending. A long period of time with no offending will be a
more positive factor than a short period of time.
An applicant may have also been involved in activities that indicate they may be of
good character. For example, they may have,
• engaged with programmes or activities aimed at addressing the cause of the
offending, such as (but not limited to) treatments aimed at reduction of alcohol
consumption, or drug dependency or anger management courses
• actively engaged with voluntary work, charity work, or actively promoted the
reduction of crime
The list of factors is indicative, not exhaustive.
You didn't cause serious harm, and don't have a pattern of previously offending. Can you bring evidence of your good standing in the community (eg volunteering)? Have you spoken to DVLA and see if there can be any leniency as it was a mistake in good faith?
I haven't seen personally many cases like yours before - usually drink driving raises more concerns than a clamped car, however as you say 3 FPNs in a short time and just before applying could be a spot on your character. Have you considered speaking to a solicitor? The other thing I can suggest is for you to delay your application by a year and take up some volunteering or safe driving courses to show you understood your mistake and will amend your behaviour. I am probably being overly cautious as this is your first ever relatively serious offence.
All advice comes from personal research and experience and should not be regarded as professional opinion.