You can have the registration complete way before you are ready to fly.  I think most people wait until the last minute to keep below the radar for sales tax.  But you can have a registered aircraft that's still in pieces.

Randy,

 

What Mike says about registration is generally correct.

 

1.  Like weight and balance, aircraft registration is just another requirement, along with a complete operational airplane, that is needed to satify the FAA or DAR final inspection and issuance of the airworthiness certificate.  You can reserve an N-number and/or actually register the number before you even know what the engine serial number will be.  Reservation requires no bill of sale while registration does.

 

2. In my state, IL, it may be useful (and more legal) to Federally Register your kit ASAP after receiving it and thus pay tax on just the kit price, rather than its increased value when complete where you might have to prove that certain taxes had alreay been paid on components bought within your state.  IL receives the FAA data and they will send a nasty letter asking for tax monies on newly registered aircraft.  Note that in this state, the sales tax on the kit is actually due within 30 days of taking possesion of the kit.  It is useful to have the N-number when you pay the tax to avoid any bureaucratic confusion later.

 

3.  Sales taxes are never reduced - pay early, pay less.

 

4. Some states have a yearly fee (personal property tax?) - perhaps this becomes a meaningful consideration.

 

5. Keep abreast of your state laws - they change the most when you are not looking.