How popular is the "Sold Secure" certification among reasonable-quality lock makers? I'm a recent convert to cycling, having moved to Amsterdam, and I intend to buy a U-lock for a bike I'm getting.

Now, people have recommended that I buy U-locks with a "sold secure" label - but in a couple of bike shops I've been to I haven't seen any items with this label. Granted, there wasn't that much variety, but it did make me wonder - is that certification very popular with lock manufacturers (of reasonable-quality locks)? Or is it more so for manufacturers in other countries than here? I need to decide whether to limit myself to locks with the certification or think of some other way to evaluate locks.
You might have a bit more luck doing things the other way around - go to the Sold Secure web site and read off a list of compliant locks. When I was buying, I took this approach, chose the locks and then bought them online.

Also, bear in mind that Sold Secure originated in the UK, so possibly lock manufacturers who sell mostly outside of the UK market might not consider it worthwhile to worry about this badge. But having said that, I can see right now the Sold Secure sticker on both Kryptonite and Abus web sites (two of the biggest names, neither UK-based) against certain of their locks.

As regards how useful the Sold Secure branding is, you should be aware that this is pretty debatable. I've heard the scheme described as a marketing scam by the insurance/lock industries.

That having been said, I have a bike insurance policy which specifies that I need such-and-such a grade of Sold Secure lock in order for the policy to be valid. So, putting aside the issue of how "good" the lock is (in terms of protection against theft), in terms of me complying with the insurance policy it is a no-brainer just to use a lock with this badge on it.

Note that Sold Secure also have a scheme that applies to motorcycle locks, if that helps you to find a stockist. I have a chain which is rated as "silver" for a motorbike, but "gold" for a bicycle.