Domestic reverse charge applies when a UK customer buys mobile phones or computer chips. The customer, not the supplier, records the VAT on their VAT Return.
Usually, when you sell goods or services to another VAT registered business, you include VAT on your invoice and record it on your VAT Return.
Under the reverse charge, you don’t add VAT to your sales invoice. Still show the VAT amount and state that the reverse charge rules apply. The customer accounts for the VAT as output tax and can normally reclaim the same amount as input tax, subject to the usual VAT recovery rules.
Specify that VAT Reverse Charge applies on the sales invoice for those customers who buy mobile phones and computer chips from you.
To do this, read reverse charge VAT and CIS. For a new customer, select the checkbox from the Account Details section.
If you've set the customer up to use domestic reverse charge, a checkbox shows on the invoice.
The effect on the VAT return is:

Any invoice where reverse charge applies shows on your VAT Return when you raise it, rather than when your customer pays it.
Any invoice where reverse charge applies shows in the box 6 figure, but not in the flat rate calculation.