The UK has internet--so no reason you cannot e-file from the UK. You can e-file from anywhere in the world that has internet access. However---do not wait until the last minute. Just in case you encounter any issues when you try to e-file (like duplicate SSN's you are not expecting etc.) you need to allow yourself time to print sign and mail the return if it becomes necessary. If you cannot e-file for any reason--the back up plan is to mail it, and it will need to be postmarked by the deadline of July 15 if you owe tax due. If you are getting a refund, filing after the deadline is not a big deal.