The General Treasury of Social Security recently published the RED Newsletter 07/2026, which includes important clarifications regarding the application of Social Security contribution rebates for research personnel.
The specific rules governing these rebates are set forth in Royal Decree 475/2014, dated June 13, on rebates on Social Security contributions for research personnel. Subsequently, Royal Decree-Law 1/2023, dated January 10, introduced significant changes to that system and established a new framework applicable to employment incentives.
Key Changes in the Application of Social Security Tax Credits
The new bulletin maintains the general framework of the incentive and provides greater operational clarity on how these situations should be identified within the General Treasury of Social Security’s registration system. In practice, this clarification enhances certainty in the application of the rebate by specifying how certain data must be reported to avoid procedural issues.
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How to Identify Eligible Research Staff: Value 9916 and Contract Codes
The General Treasury of Social Security reminds users that registration situations to which the tax credit applies must be identified using the code 9916 in the “Special Employment Relationship” field. Furthermore, this code must be linked to certain types of contracts in the General Treasury of Social Security, even when the code does not exactly match the contract formalized and reported to the State Public Employment Service. This clarification is particularly important, as the bulletin establishes a correspondence between the contract codes reported to the State Public Employment Service and the codes that must be entered in the General Treasury of Social Security in order to correctly apply the measure. In this way, the General Treasury of Social Security specifies which code must be used for the purposes of the tax credit when the code reported to the State Public Employment Service is different.
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Application of the tax credit to workers who are already registered
Another key issue addressed in the bulletin is the possibility of applying the tax credit retroactively to employees who are already registered with the company, even if the tax credits were not yet applicable during the initial registration period. In these cases, the employee must initially be registered without a “Special Employment Relationship.” When the tax credit becomes applicable, the employee’s registration from the previous period must be canceled, and a new registration must be processed with the code 9916.
Therefore, the bulletin confirms an important operational guideline: there may be an initial registration period without a subsidy and without a Special Employment Relationship, and subsequently, once the requirements for applying the incentive are met, the subsidized status may begin through a new registration under Special Employment Relationship 9916.
This clarification is particularly useful in cases where, following the amendment introduced by Royal Decree-Law 1/2023, the tax credit for certain workers has not yet been initiated because it was not applied at the time of their initial registration. To the extent that these workers currently meet the required criteria, the form allows the situation to be rectified by deregistering them from the “Special Employment Relationship” period and re-registering them under Special Employment Relationship code 9916.
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Periods of research staff not eligible for bonuses: use of value 9938
The bulletin also regulates the use of code 9938, identified as “Research, Development, and Innovation Personnel—Non-Incentivized.” This code must be used when, during a period of employment in which the incentivized status had already been initiated using code 9916, there is a period during which the incentive does not apply. Consequently, code 9938 allows for the identification of non-subsidized periods once the employee has already been correctly enrolled in the subsidized research staff program.
Why This Update Is Relevant to Businesses
In summary, this update provides greater certainty in the administrative management of these tax credits, particularly in five areas:
- correct identification of research personnel eligible for the bonus using the code 9916;
- equivalence between contract codes of the State Public Employment Service and contract codes of the General Treasury of Social Security;
- the possibility of initiating the tax credit for employees who are already enrolled, even if it is not yet applicable during the initial period;
- Operating procedure for initiating this tax credit by terminating the period under a Special Employment Relationship and re-registering under a Special Employment Relationship 9916;
- Treatment of periods during which the employee is a research staff member but the tax credit does not apply, using code 9938.
For companies carrying out R&D&I projects, these clarifications represent an opportunity to review both the situations currently eligible for the tax credit and those research employees who, although already on the payroll, may now meet the requirements to qualify for the incentive. It is also advisable to verify whether there are employees who meet the required conditions but are not yet included in the tax credit program.
This update enhances the reliability of the incentive program and allows for a more precise review to ensure that registrations, changes, and eligible periods are correctly reported to the General Treasury of the Social Security System. Conducting a preliminary review of the employment, technical, and documentation status streamlines this process, reduces risks in reporting, and helps ensure the incentive is utilized with greater certainty. In a context where investment in innovation requires planning and oversight, proper management of these rebates can help optimize costs and strengthen the company’s strategy for funding its research activities.
José Miguel Sanabria, Consultant in the Legal andInnovation Financing Department at Elzaburu