Work in taiwan currently employed and own arc

What you are saying does not make sense. UID numbers (equivalent to ARC or APRC number) are assigned for life since around 2007. What’s there not to understand about it? You will not get a different number from when you apply for a new ARC or an extension of your ARC or APRC. Even if there are interruptions between your residence periods.

I believe it’s 統一證號 for humans, 統一編號 for companies.

Sigh

I am trying to explain to the OP and other newbies who make the mistake of thinking that if their ARC has a date printed on it, it is valid to that date. It is not.

They will make the same mistake if the number is the same. “But I thought that I had already completed my 5 years?” I can hear them scream. Yet, the system shows gaps in their residence time…

My point is whether it is the same number, it is still irrelevant in terms of its validity, as what matters is that the ARC is valid meaning supported by either a work permit or family situation, and if you want an APRC, that there is a continuos residence as per official records within the 5 year period they ask for, with provisions for lenience withstanding.

So having the same number makes no difference in terms of requesting an APRC. What matters most is that the ARC is backed, valid, and has been so for the period required.

What kind of provisions for lenience exist?

There is leeway as they will allow a gap say of 3 months, I think. They want to help, just don’t get in their way with an aggressive attitude. Be open and sincere and they will help you.

I wonder if they are as lenient with naturalization.

As long as you are game, they mostly are.