If it's two of us, and the bill is say anything over like £25 i round up to £30 for under £50, so £46.50 would be straight £50. If it's over £50 say, £67 and a good meal i'd make it £75, if it wasn't that good but worth tipping would be £70 plus and loose change. For 4 people or more try to give at least 10-15% or roughly £5 max per person plus change. If it's a shoddy meal, will leave loose change or nothing. But over here, we don't have constant refills or top ups except in American Restruants, which are so ridiculously overpriced already don't tend to tip.
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