From The SIA website
If you already hold a Door Supervisor, Close Protection, Security Guard or CVIT licence you will need to apply for a new one before your current one expires. Don't wait until after it expires: you need a valid licence to work legally and there's no grace period between licences.
We will accept licence renewals up to four months in advance of when your current licence expires. If your application for renewal is successful and is processed before your existing licence expires, you will not be disadvantaged as the new licence will expire three years after your current licence expires.
If you submit your application earlier than this it will be treated as a new application. If the application is successful your new licence will expire three years from when we grant it. It will not be extended by the time remaining on your current licence.
A licence renewal costs the same as a new application (£245) and requires the same form. There are two ways to request an application form:
Please note: the current version of the application form (LAF04) has been in use since February 2010. We do not accept applications made on the previous version of the form (LAF02).
Fill in your application form online
Our e-Fill service lets you fill in your application form online and then print it yourself or request that we print it and post it to you.
Request a blank application form
You can request an application pack by filling in our online form or calling 0844 892 1025 (lines open 8am until 8pm Mon-Fri).
Request an application pack here
Identification Documents
When you send us your application form you may also need to send your supporting documents. However, if you have previously submitted one of the photographic group A documents to us (i.e. not a birth certiticate or adoption certificate) in support of a licence application that was successful, you do not need to re-send any documents unless your name or address have changed.
If your name has changed since the last time you applied or you did not previously submit a photographic group A document you will need to submit a new, complete set of identity documents.
If your address has changed since your last application you will need to send one group B document showing your new address even if you have already informed us of this change.
Checklist details of what is required.