Freq traveller can renew your passport without sending your current passport back?

Im a little confused regarding renewing my passport. I use my passport each week travelling to the Netherlands, where we have a project under construction. My passport expires in July and I had been told that it may be possible to renew your passport in advance of your current one expiring without sending in your current passport.
I have tried to call the passport office to confirm this but cannot get through and on their website it states that even with an appointment, turnaround time is 15 days.

Does anyone know if you can renew your passport without sending your current passport back

My brother does a lot of travelling for work (as is nearly lives on a plane) and frequently has to apply for visas that can take weeks. So he has a second/supplementary passport. I'm not sure if it is a full second passport or just one that can be used for applying for visa. But the passport office definitely have a process to facilitate this.

Secondary passports while still possible are a lot trickier to get than was previously the case - just having lots of stamps in your passport is no longer sufficient (Passport office can help you with the criteria, it includes a board level authorisation from your employer I believe)

If you are renewing your passport that expires in July though you're okay .. provided the current passport you hold expires within 6 months you are allowed to keep the old passport while the renewal of the current one is processed.

See - [broken link removed]

"A photocopy of the photograph page of your old/current passport (if your current passport is valid for more than 6 more months you must send your current passport)"

So you shouldn't have a problem with this.