In the event of a no-deal Brexit, there will be an impact on how public sector procurements are advertised, and therefore how to go about searching for them.
The exact details are not yet finalised, but the following summarises what is known so far.
Current situation
Currently there are a set of procurement regulations that must be followed, which include the fact that all public sector procurements above EU thresholds must legally be publicised through the Official Journal of the EU (OJEU). This is the central contract notice board for all EU member states where live contract opportunities in all EU countries, including the UK, can be viewed and searched. The EU thresholds are £181,302 for supplies and services and £4,551,413 for works. All opportunities can be viewed here: https://ted.europa.eu/TED/search/search.do
Below these EU thresholds, all UK public contracts must be advertised on the government website Contracts Finder (or the sites specific to Scotland, Wales, Northern Ireland and the Ministry of Defence). The threshold for contracts to be posted here is £10,000 for central government authorities and £25,000 for the rest of the public sector. Opportunities can be viewed here: https://www.contractsfinder.service.gov.uk/Search
After a no-deal Brexit
In the event of a no-deal Brexit, the UK government has stated that the procurement regulations will remain broadly the same. However, one key difference will be that after a no-deal Brexit, contracting authorities must advertise their opportunities on a new UK e-notification service instead of OJEU. This e-notification service is not yet available, but the UK government has stated that it will be available on exit day, 31stOctober 2019 (or 1st June if the UK does not participate in the European elections on 23rd May).
The requirement to advertise on Contracts Finder (and the other location specific domestic sites) will remain unchanged following a no-deal Brexit.
So how do I search for tenders after a no-deal Brexit?
To search for opportunities in the UK, you will need to use the new UK e-notification service, the details of which are still to be released, but Complete Tenders will provide the information and a link as soon as we have it.
You will also still be able to use Contracts Finder, as now, to search for opportunities.
To search for opportunities in the EU, you will still be able to use OJEU, however, in the event of a no-deal Brexit, UK companies will have the same status as companies from countries without an agreement from the EU regarding the EU procurement market, and therefore will be subject to the rules that currently apply to those countries. This may make winning tenders more difficult. The EU has published guidelines on this here: https://ec.europa.eu/info/sites/info/files/file_import/public_procurement_en.pdf
Additionally, Complete Tenders provides a comprehensive free tender listings service which currently combines OJEU and Contracts Finder; this will be updated to include the new UK e-notification service in the event of a no-deal Brexit. This can be found here: https://www.completetenders.com/open-tenders/
What if I find a tender on OJEU just before a no-deal Brexit?
Clearly some of the tenders advertised on OJEU will have a submission date past the Brexit date of 31st October 2019. The exact details of what will happen and what rules will apply in the event of a no-deal Brexit have not yet been published, but, for example, any contract award notices for those tenders will need be published on the new UK e-notification service after 31st October 2019.
As you don’t actually apply for a tender through OJEU, but use the specific procurement portal or other mechanism determined by the contracting organisation, the fact that you found the tender through OJEU before a no-deal Brexit should have no impact on submitting your tender application.