There's a bit of confusion on this rule (Standing Rule 601.1) and since it changed at the beginning of the 2007/2008 show season - but some of the paperwork still hasn't been updated - here's the latest position:
Your cat does not need to be registered with TICA to be shown with TICA (unless it is being shown in the New Traits or New Breeds classes - you must have a TICA registration number first before entering these classes).
In order to be awarded a title, your cat must first be registered with TICA. However, all title points and Finals accumulated whilst the cat was not registered are eligible to be included in any title claims.
Scores for Regional and International Awards are only accumulated for cats registered with TICA. Your cat's first show (where it was shown unregistered) will count for points towards these awards but you must apply to register the cat before its second show, to avoid losing any regional points at that second and subsequent shows. For the purposes of this rule, back-to back shows count as "one show".
The key words are "apply to register". The date that paperwork arrives in the EO is the effective date of registration, since it may take a while for it to be processed.
Once the registration number is in the show catalogue, then the accumulation of award points is done automatically by the Executive Office when they have checked the catalogue after the show. The scores are calculated on an annual basis (1 May to 30 April).
For any show where a cat is in the Master show catalogue without a registration number, then the exhibitor must apply to the Executive Office asking for those shows to be scored for Regional/International Awards - and you have until 7th May each show year to do this. You can do this by e-mail to email@example.com .
NB: cat is shorthand for kitten, adult, alter, HHP or HHP Kitten. Registered kittens (whether pedigree or HHP) are not eligible for titles but can earn Regional Winner (RW) or International Winner (IW) awards.