There are two ways you can submit your monthly Supplementary Declarations (SDs):
- via the internet
- through the Electronic Data Interchange (EDI)/EDIFACT
You can complete your SDs and file them online on the uktradeinfo website. You can use either an online form or use a Comma Separated Variable (CSV) file compiled offline. You'll need to register and obtain a username and password to use this service. Read more about Intrastat Electronic Submissions.
You can also use the EDI system to file your returns via email. You'll need to supply the file in a specific format to do so.
The period covered and monthly cut-off date
You must submit SDs on a monthly basis so that they are received by the 21st day of the month following the period for which you are reporting transactions - eg April SDs must be submitted by 21st of May. A calendar month is the normal reference period and you must use four digits to show the month and year for which you are reporting transactions - (mmyy) - eg 0418 for April 2018.
If your business is approved to use non-standard VAT periods, the reference period can be either the calendar month in which the goods arrive in - or are dispatched from - the UK, or the calendar month of the VAT tax point.
You can choose the method that will best enable your business to meet its Intrastat duties. Note however, that if your business has 13 x 4 - week VAT periods, you must ensure that one of your Intrastat periods includes one eight-week period to allow 12 submission periods in total.
If you exceed the threshold on both arrivals and dispatches, you must separately provide information on your inbound and outbound trade and submit both forms.
The data you provide on SD forms for Intrastat purposes is also used for purposes of VAT regulations.
You can submit as many SDs as you like each month. Submitting nil returns will prevent you from being contacted for missing declarations and timely, complete and accurate submissions will avoid costly penalty action.
It is your responsibility to monitor your EU trade to determine when you must submit an SD. HMRC will also be monitoring the value of your EU trade and may write to you from time to time to check that your records and theirs tally.