400% deposit bonus casinos are online gambling platforms that offer players a bonus worth four times their initial deposit. This means if you deposit £50, you’ll receive an extra £200 in bonus funds, that gives you a total of £250 to play with. 400% deposit bonus casinos use high-percentage bonuses to attract new players and reward regular ones, often as part of a welcome package or special promotion. Jaw-dropping 400% casino bonus campaigns are luxury-something, hence they are a big rarity for the UK market. Subsequently, on this page, you’ll mostly find promotions with alternative percentages that give Brits the closest possible experience. Most importantly, all the deals come from proven and tested casinos with a coveted UKGC licence. All brands follow local gambling laws and regulations.