Self Assessment: Attachments to online return

General Information

From 1 November 2006, an additional feature will allow you to submit an online attachment with your online Self Assessment return.

In the majority of cases, it should not be necessary for you to attach accompanying material to your return. If you want to give us more information in support of your entries, you can enter this in the ‘Additional Information’ box.

There may be some situations, however, where we require you to send us additional supporting documentation with your online Self Assessment return, and in these circumstances, the online Self Assessment attachments feature can be used.

One example of where we would expect additional documentation is in the case of the ‘Capital Gains’ supplementary page, where a claim for gifts hold-over relief is being made.

If, after reading all the relevant Self Assessment return guidance, you are still unsure whether an attachment is appropriate, please ring either your tax office or, when the office is closed, the self assesment Helpline.

Technical Detail

To successfully use the online Self Assessment attachments feature, please note the following:

• The attachment will need to be a true PDF (Portable Document Format) file which can be created by, for example, using software such as Adobe Acrobat Writer or by using a basic scanner.
• Total file size must not exceed 5mb. Typically we would expect any attachment you submit to be well below this limit and instances where the upper limit is reached to be rare. Examples of what a 5mb PDF file might look like are; 500 pages of plain text – generated from Microsoft Word or Excel; or 150 pages scanned in black and white at a resolution of 150dpi; or 7 pages scanned in colour at a resolution of 300dpi). To minimise the size when creating a PDF file, we recommend that you ensure there are no logos or images within the document and, if using a scanner, that a low scanning resolution is used, i.e. 150dpi.
• The online Self Assessment attachments feature will transmit PDF files quicker if using a broadband (or equivalent) connection. If you use a telephone dial-up facility (i.e. not broadband or equivalent), the speed with which PDFs will transmit may be very slow, and so, if possible, you should avoid peak periods, i.e. 10:00–16:00 weekdays and the week leading up to 31 Jan filing date.
• Any attachment must be virus free and must not have additional files embedded within it.
• The HM Revenue and Customs online Self Assessment product will not allow submission of more than 20 attachments with your online Self Assessment return.

Additional Considerations:

• The online Self Assessment return and any accompanying attachments are processed as a single online file
• If you do not observe the above requirements, neither your online SA return nor any accompanying attachments will be accepted by HMRC.

What we do on receipt of the Self Assessment online return and attachment

We will examine attachments submitted to ensure they do not contain information relevant to any enquiry that we may make prior to opening such an enquiry.

We will not routinely review attachments and you should therefore not attach any information that is not directly related to the return.

You are reminded that if you do not successfully submit your Self Assessment return, with or without attachments, by january deadline; you will incur a late filing penalty.