When a domain expires its not a simple case of re-registering, it goes into several periods after where the person or business can renew the account. If you plan to use the domain again then you should proceed with renewing it, and then transferring.
Qoute from an answer I left a few months back:
Domain Expiration when transfer is processing, will I lose it?
Expiring Domains Explained
Whenever a domain expires you do not lose your domain straight away,
ICAN has policy's in place that gives registers more time to renew
their domain once it has expired. ICANN refers to these as a Grace
Period and a Redemption Period. There is actually 2 stages until
entering the 3rd stage where your domain becomes registerable to other
Stage 1: Grace Period
As soon as your domain expires your domain enters the Grace Period,
this stage means that you can renew your domain within 30 days without
additional charges apart from the standard renewal cost set by the
registrar. No one else can take your domain during this period and
some domain registrars even allow you to transfer during this period
while many do not. Failing to renew your domain during the standard
allowance of 30 days enters you into the Redemption Period.
Stage 2: Redemption Period
Once 30 days has passed and the domain in question remains
nonrenewable then it enters the redemption period, this stage of the
expiring process normally lasts 40 days. During this period again like
the Grace Period no one can register your domain and it is still
locked to the original person who registered it. But unlike the grace
period charges to renew the domain will be much more than just the
renewal cost and this varies from registrar to registrar.
Stage 3 & 4: Pending Delete & Dropped Domain
Failing to renew your domain during the grace and redemption period
will enter the final stage of it being released into the public, this
is referred to as pending delete and dropped. Whenever a .com or .net
TLD is due to drop it will drop around 11AM to 12:15 PST, It is still
renewable during these last final moments.
You actually have around 70 days to renew your domain, it doesn't
matter if its in process of being transferred the domain will still be
yours but will require renewing once transfer has completed.