If you're exporting goods on an occasional basis, there are several declaration processes which you can use.
National Export System and Customs Procedures with Economic Impact
The National Export System (NES) tracks consignments which are exported under Customs Procedures with Economic Impact (CPEI). CPEI procedures are designed to help businesses based in the European Union (EU) to compete in the global market economy. Importers can suspend paying duty and VAT on goods covered by CPEI arrangements. On re-importation duty rates may also be relaxed on consignments previously exported under Outward Processing Relief (OPR). Read more about export declarations and the National Export System.
When using Simplified Declaration Procedures (SDPs) or Local Clearance Procedures (LCPs) with OPR, after issuing a Pre-Shipment Advice (PSA) you have to wait for a Permission to Progress (P2P) message before the goods can be sent to the frontier and exported. As usual, you have to issue the Supplementary Declaration (SD) within 14 days of the date of the PSA.
Simplified OPR procedure
If you only occasionally need to export goods for repair, you can choose to use the simplified OPR procedure, which gives you the advantage of fast, electronic communication with customs, and accelerated release of your goods. However, you cannot also use export SDs for declarations you make under the simplified OPR procedure.
SDs and processing under customs control
If you wish to export either processed products or unaltered goods, once you have obtained permission you may, as an alternative to full declaration, use LCP, SDP at a Designated Export Place, or SDP at the UK frontier.