There is no standing public Qustodio discount code — the lists ranking at the top of search are almost always stale affiliate pages recycling an expired code, or a link that pays the page owner. Qustodio's real price break is annual billing and the free trial; a code, when one exists, comes from their own newsletter or a partner campaign and carries an expiry date.
How to tell a live code from a funnel. A genuine code is applied on Qustodio's own checkout and either works or returns an error there — if the "coupon" page sends you to a reseller, a comparison table or a second page of offers, the code is decoration. Never type card details anywhere but qustodio.com. Two more tells: codes rarely stack with a running promotion, and a "95% off, today only" banner is a signal of a funnel rather than a bargain.
Full disclosure: we sell a competing product. Ultimate Phone Spy is not a Qustodio affiliate and takes no commission on their sales, so judge that as you like. Our pricing has no coupon layer at all: $69.90/month, $40/month on quarterly billing, $16/month annually (pricing). Annual billing is where every vendor in this market hides its discount, ours included.
Where the products genuinely differ. Qustodio covers iPhone through Screen Time and app-level controls. Ours does not: Android 4.0+, Windows and Mac only, with device-level SMS, call logs, web history and location from a phone the account holder administers (system requirements). If the child is on an iPhone, Qustodio or the free built-in Screen Time is the right purchase and we would be the wrong one; if you want one dashboard over a family PC plus Android phones, that is the gap we fill.