the elextricity utility company supplies you with electricity at a nominal 220V, what that means is they would love to supply you with 220V exactly but it is practically impossible to do that to every property in the country. So a nominal voltage with an allowable variation, normally 10% (22V) either way.

So you could get 220V, 240V or 200V and all is OK with that.

the reason for this is that the number of volts at the substation drops according to the length and size of the cable to your house, and how much other load is on the system and a few other things,

The variation of voltage is set down by law in the UK, you can expect to get any voltage between 220V and 250V, that's a wide range. It was set this way to allow European appliances that use 220V to be sold in the UK. The reality is that if your mains voltage is as low as 220V then your lights will be dim.

When the voltage in the UK and Europe was standardized from 240v in the UK and 220v in the rest of Europe to 230v. The actual voltage remained the same, they just increased the acceptable variation. In the UK, that is still below the normal voltage, despite being high in the rest of Europe.

Your meter is probably pretty close to correct. The power Company is in the business of selling electrical energy. The higher they keep your wall socket Voltage the more electrical energy you will use. Therefore they can sell more energy per household by maintaining the Voltage on the high side of the Voltage tolerance.

Sounds O/K to me. Power voltages are set a little high so that when the load increases, the voltage can droop a little. Also, is your meter average sensing, or peak sensing, or RMS sensing. That makes a difference if the power waveform is not a pure sine wave. RMS sensing is the best.

If the nominal voltage in your area is 220VAC then expect to see 200VAC to 240VAC. Power companies in the western world generally do even better. Anything within 10% is good. You are seeing only 4.1%, which is close enough to call precision.

U.S. residential service?

Close enough. Standard service is "nominally" 230 Volts, but might vary plus or minus 10 Volts: 220 - 240 Volts. You're good.

(The single leg measurement would be nominally 115 Volts, plus or minus 5 Volts: 110 - 120 Volts.)

That voltage will go up and down depending on the time of day as demand for power goes up and down.

What country do you live in?

You're electricity is fine. Worry about something else.